Bump the .NET SDK to 7.0.100-preview.2.22153.17 and modernize the code base

global.json

@@ -1,16 +1,17 @@
 {
   "sdk": {
-    "version": "6.0.100"
+    "version": "7.0.100-preview.2.22153.17"
   },
 
   "tools": {
-    "dotnet": "6.0.100",
+    "dotnet": "7.0.100-preview.2.22153.17",
 
     "runtimes": {
       "aspnetcore": [
         "2.1.28",
         "3.1.16",
-        "5.0.7"
+        "5.0.7",
+        "6.0.0"
       ]
     }
   },

sandbox/OpenIddict.Sandbox.AspNetCore.Server/Helpers/AsyncEnumerableExtensions.cs

@@ -2,13 +2,8 @@
 
 public static class AsyncEnumerableExtensions
 {
-    public static Task<List<T>> ToListAsync<T>(this IAsyncEnumerable<T> source)
+    public static Task<List<T>> ToListAsync<T>(this IAsyncEnumerable<T> source!!)
     {
-        if (source is null)
-        {
-            throw new ArgumentNullException(nameof(source));
-        }
-
         return ExecuteAsync();
 
         async Task<List<T>> ExecuteAsync()

shared/OpenIddict.Extensions/Helpers/OpenIddictHelpers.cs

@@ -20,18 +20,8 @@ internal static class OpenIddictHelpers
     /// <param name="type">The type to introspect.</param>
     /// <param name="definition">The generic type definition.</param>
     /// <returns>A <see cref="Type"/> instance if the base type was found, <c>null</c> otherwise.</returns>
-    public static IEnumerable<Type> FindGenericBaseTypes(Type type, Type definition)
+    public static IEnumerable<Type> FindGenericBaseTypes(Type type!!, Type definition!!)
     {
-        if (type is null)
-        {
-            throw new ArgumentNullException(nameof(type));
-        }
-
-        if (definition is null)
-        {
-            throw new ArgumentNullException(nameof(definition));
-        }
-
         if (!definition.IsGenericTypeDefinition)
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0263), nameof(definition));

src/OpenIddict.Abstractions/OpenIddictBuilder.cs

@@ -17,8 +17,8 @@ public class OpenIddictBuilder
     /// Initializes a new instance of <see cref="OpenIddictBuilder"/>.
     /// </summary>
     /// <param name="services">The services collection.</param>
-    public OpenIddictBuilder(IServiceCollection services)
-        => Services = services ?? throw new ArgumentNullException(nameof(services));
+    public OpenIddictBuilder(IServiceCollection services!!)
+        => Services = services;
 
     /// <summary>
     /// Gets the services collection.

src/OpenIddict.Abstractions/OpenIddictExtensions.cs

@@ -17,15 +17,8 @@ public static class OpenIddictExtensions
     /// <param name="services">The services collection.</param>
     /// <remarks>This extension can be safely called multiple times.</remarks>
     /// <returns>The <see cref="OpenIddictBuilder"/>.</returns>
-    public static OpenIddictBuilder AddOpenIddict(this IServiceCollection services)
-    {
-        if (services is null)
-        {
-            throw new ArgumentNullException(nameof(services));
-        }
-
-        return new OpenIddictBuilder(services);
-    }
+    public static OpenIddictBuilder AddOpenIddict(this IServiceCollection services!!)
+        => new OpenIddictBuilder(services);
 
     /// <summary>
     /// Provides a common entry point for registering the OpenIddict services.
@@ -34,18 +27,8 @@ public static class OpenIddictExtensions
     /// <param name="configuration">The configuration delegate used to register new services.</param>
     /// <remarks>This extension can be safely called multiple times.</remarks>
     /// <returns>The <see cref="IServiceCollection"/>.</returns>
-    public static IServiceCollection AddOpenIddict(this IServiceCollection services, Action<OpenIddictBuilder> configuration)
+    public static IServiceCollection AddOpenIddict(this IServiceCollection services!!, Action<OpenIddictBuilder> configuration!!)
     {
-        if (services is null)
-        {
-            throw new ArgumentNullException(nameof(services));
-        }
-
-        if (configuration is null)
-        {
-            throw new ArgumentNullException(nameof(configuration));
-        }
-
         configuration(services.AddOpenIddict());
 
         return services;

src/OpenIddict.Abstractions/Primitives/OpenIddictConverter.cs

@@ -19,13 +19,8 @@ public class OpenIddictConverter : JsonConverter<OpenIddictMessage>
     /// </summary>
     /// <param name="typeToConvert">The type to convert.</param>
     /// <returns><c>true</c> if the type is supported, <c>false</c> otherwise.</returns>
-    public override bool CanConvert(Type typeToConvert)
+    public override bool CanConvert(Type typeToConvert!!)
     {
-        if (typeToConvert is null)
-        {
-            throw new ArgumentNullException(nameof(typeToConvert));
-        }
-
         return typeToConvert == typeof(OpenIddictMessage) ||
                typeToConvert == typeof(OpenIddictRequest) ||
                typeToConvert == typeof(OpenIddictResponse);
@@ -38,13 +33,8 @@ public class OpenIddictConverter : JsonConverter<OpenIddictMessage>
     /// <param name="typeToConvert">The type of the deserialized instance.</param>
     /// <param name="options">The JSON serializer options.</param>
     /// <returns>The deserialized <see cref="OpenIddictMessage"/> instance.</returns>
-    public override OpenIddictMessage Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+    public override OpenIddictMessage Read(ref Utf8JsonReader reader, Type typeToConvert!!, JsonSerializerOptions options)
     {
-        if (typeToConvert is null)
-        {
-            throw new ArgumentNullException(nameof(typeToConvert));
-        }
-
         using var document = JsonDocument.ParseValue(ref reader);
 
         return typeToConvert == typeof(OpenIddictMessage)  ? new OpenIddictMessage(document.RootElement.Clone()) :
@@ -59,18 +49,8 @@ public class OpenIddictConverter : JsonConverter<OpenIddictMessage>
     /// <param name="writer">The JSON writer.</param>
     /// <param name="value">The instance.</param>
     /// <param name="options">The JSON serializer options.</param>
-    public override void Write(Utf8JsonWriter writer, OpenIddictMessage value, JsonSerializerOptions options)
+    public override void Write(Utf8JsonWriter writer!!, OpenIddictMessage value!!, JsonSerializerOptions options)
     {
-        if (writer is null)
-        {
-            throw new ArgumentNullException(nameof(writer));
-        }
-
-        if (value is null)
-        {
-            throw new ArgumentNullException(nameof(value));
-        }
-
         value.WriteTo(writer);
     }
 }

src/OpenIddict.Abstractions/Primitives/OpenIddictExtensions.cs

@@ -25,70 +25,37 @@ public static class OpenIddictExtensions
     /// Extracts the authentication context class values from an <see cref="OpenIddictRequest"/>.
     /// </summary>
     /// <param name="request">The <see cref="OpenIddictRequest"/> instance.</param>
-    public static ImmutableArray<string> GetAcrValues(this OpenIddictRequest request)
-    {
-        if (request is null)
-        {
-            throw new ArgumentNullException(nameof(request));
-        }
-
-        return GetValues(request.AcrValues, Separators.Space);
-    }
+    public static ImmutableArray<string> GetAcrValues(this OpenIddictRequest request!!)
+        => GetValues(request.AcrValues, Separators.Space);
 
     /// <summary>
     /// Extracts the prompt values from an <see cref="OpenIddictRequest"/>.
     /// </summary>
     /// <param name="request">The <see cref="OpenIddictRequest"/> instance.</param>
-    public static ImmutableArray<string> GetPrompts(this OpenIddictRequest request)
-    {
-        if (request is null)
-        {
-            throw new ArgumentNullException(nameof(request));
-        }
-
-        return GetValues(request.Prompt, Separators.Space);
-    }
+    public static ImmutableArray<string> GetPrompts(this OpenIddictRequest request!!)
+        => GetValues(request.Prompt, Separators.Space);
 
     /// <summary>
     /// Extracts the response types from an <see cref="OpenIddictRequest"/>.
     /// </summary>
     /// <param name="request">The <see cref="OpenIddictRequest"/> instance.</param>
-    public static ImmutableArray<string> GetResponseTypes(this OpenIddictRequest request)
-    {
-        if (request is null)
-        {
-            throw new ArgumentNullException(nameof(request));
-        }
-
-        return GetValues(request.ResponseType, Separators.Space);
-    }
+    public static ImmutableArray<string> GetResponseTypes(this OpenIddictRequest request!!)
+        => GetValues(request.ResponseType, Separators.Space);
 
     /// <summary>
     /// Extracts the scopes from an <see cref="OpenIddictRequest"/>.
     /// </summary>
     /// <param name="request">The <see cref="OpenIddictRequest"/> instance.</param>
-    public static ImmutableArray<string> GetScopes(this OpenIddictRequest request)
-    {
-        if (request is null)
-        {
-            throw new ArgumentNullException(nameof(request));
-        }
-
-        return GetValues(request.Scope, Separators.Space);
-    }
+    public static ImmutableArray<string> GetScopes(this OpenIddictRequest request!!)
+        => GetValues(request.Scope, Separators.Space);
 
     /// <summary>
     /// Determines whether the requested authentication context class values contain the specified item.
     /// </summary>
     /// <param name="request">The <see cref="OpenIddictRequest"/> instance.</param>
     /// <param name="value">The component to look for in the parameter.</param>
-    public static bool HasAcrValue(this OpenIddictRequest request, string value)
+    public static bool HasAcrValue(this OpenIddictRequest request!!, string value)
     {
-        if (request is null)
-        {
-            throw new ArgumentNullException(nameof(request));
-        }
-
         if (string.IsNullOrEmpty(value))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0177), nameof(value));
@@ -102,13 +69,8 @@ public static class OpenIddictExtensions
     /// </summary>
     /// <param name="request">The <see cref="OpenIddictRequest"/> instance.</param>
     /// <param name="prompt">The component to look for in the parameter.</param>
-    public static bool HasPrompt(this OpenIddictRequest request, string prompt)
+    public static bool HasPrompt(this OpenIddictRequest request!!, string prompt)
     {
-        if (request is null)
-        {
-            throw new ArgumentNullException(nameof(request));
-        }
-
         if (string.IsNullOrEmpty(prompt))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0178), nameof(prompt));
@@ -122,13 +84,8 @@ public static class OpenIddictExtensions
     /// </summary>
     /// <param name="request">The <see cref="OpenIddictRequest"/> instance.</param>
     /// <param name="type">The component to look for in the parameter.</param>
-    public static bool HasResponseType(this OpenIddictRequest request, string type)
+    public static bool HasResponseType(this OpenIddictRequest request!!, string type)
     {
-        if (request is null)
-        {
-            throw new ArgumentNullException(nameof(request));
-        }
-
         if (string.IsNullOrEmpty(type))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0179), nameof(type));
@@ -142,13 +99,8 @@ public static class OpenIddictExtensions
     /// </summary>
     /// <param name="request">The <see cref="OpenIddictRequest"/> instance.</param>
     /// <param name="scope">The component to look for in the parameter.</param>
-    public static bool HasScope(this OpenIddictRequest request, string scope)
+    public static bool HasScope(this OpenIddictRequest request!!, string scope)
     {
-        if (request is null)
-        {
-            throw new ArgumentNullException(nameof(request));
-        }
-
         if (string.IsNullOrEmpty(scope))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0180), nameof(scope));
@@ -163,13 +115,8 @@ public static class OpenIddictExtensions
     /// </summary>
     /// <param name="request">The <see cref="OpenIddictRequest"/> instance.</param>
     /// <returns><c>true</c> if the request is a response_type=none request, <c>false</c> otherwise.</returns>
-    public static bool IsNoneFlow(this OpenIddictRequest request)
+    public static bool IsNoneFlow(this OpenIddictRequest request!!)
     {
-        if (request is null)
-        {
-            throw new ArgumentNullException(nameof(request));
-        }
-
         if (string.IsNullOrEmpty(request.ResponseType))
         {
             return false;
@@ -190,13 +137,8 @@ public static class OpenIddictExtensions
     /// </summary>
     /// <param name="request">The <see cref="OpenIddictRequest"/> instance.</param>
     /// <returns><c>true</c> if the request is a code flow request, <c>false</c> otherwise.</returns>
-    public static bool IsAuthorizationCodeFlow(this OpenIddictRequest request)
+    public static bool IsAuthorizationCodeFlow(this OpenIddictRequest request!!)
     {
-        if (request is null)
-        {
-            throw new ArgumentNullException(nameof(request));
-        }
-
         if (string.IsNullOrEmpty(request.ResponseType))
         {
             return false;
@@ -218,13 +160,8 @@ public static class OpenIddictExtensions
     /// </summary>
     /// <param name="request">The <see cref="OpenIddictRequest"/> instance.</param>
     /// <returns><c>true</c> if the request is an implicit flow request, <c>false</c> otherwise.</returns>
-    public static bool IsImplicitFlow(this OpenIddictRequest request)
+    public static bool IsImplicitFlow(this OpenIddictRequest request!!)
     {
-        if (request is null)
-        {
-            throw new ArgumentNullException(nameof(request));
-        }
-
         if (string.IsNullOrEmpty(request.ResponseType))
         {
             return false;
@@ -272,13 +209,8 @@ public static class OpenIddictExtensions
     /// </summary>
     /// <param name="request">The <see cref="OpenIddictRequest"/> instance.</param>
     /// <returns><c>true</c> if the request is an hybrid flow request, <c>false</c> otherwise.</returns>
-    public static bool IsHybridFlow(this OpenIddictRequest request)
+    public static bool IsHybridFlow(this OpenIddictRequest request!!)
     {
-        if (request is null)
-        {
-            throw new ArgumentNullException(nameof(request));
-        }
-
         if (string.IsNullOrEmpty(request.ResponseType))
         {
             return false;
@@ -339,13 +271,8 @@ public static class OpenIddictExtensions
     /// <c>true</c> if the request specified the fragment response mode or if
     /// it's the default value for the requested flow, <c>false</c> otherwise.
     /// </returns>
-    public static bool IsFragmentResponseMode(this OpenIddictRequest request)
+    public static bool IsFragmentResponseMode(this OpenIddictRequest request!!)
     {
-        if (request is null)
-        {
-            throw new ArgumentNullException(nameof(request));
-        }
-
         if (string.Equals(request.ResponseMode, ResponseModes.Fragment, StringComparison.Ordinal))
         {
             return true;
@@ -372,13 +299,8 @@ public static class OpenIddictExtensions
     /// <c>true</c> if the request specified the query response mode or if
     /// it's the default value for the requested flow, <c>false</c> otherwise.
     /// </returns>
-    public static bool IsQueryResponseMode(this OpenIddictRequest request)
+    public static bool IsQueryResponseMode(this OpenIddictRequest request!!)
     {
-        if (request is null)
-        {
-            throw new ArgumentNullException(nameof(request));
-        }
-
         if (string.Equals(request.ResponseMode, ResponseModes.Query, StringComparison.Ordinal))
         {
             return true;
@@ -404,15 +326,8 @@ public static class OpenIddictExtensions
     /// <c>true</c> if the request specified the form post response mode or if
     /// it's the default value for the requested flow, <c>false</c> otherwise.
     /// </returns>
-    public static bool IsFormPostResponseMode(this OpenIddictRequest request)
-    {
-        if (request is null)
-        {
-            throw new ArgumentNullException(nameof(request));
-        }
-
-        return string.Equals(request.ResponseMode, ResponseModes.FormPost, StringComparison.Ordinal);
-    }
+    public static bool IsFormPostResponseMode(this OpenIddictRequest request!!)
+        => string.Equals(request.ResponseMode, ResponseModes.FormPost, StringComparison.Ordinal);
 
     /// <summary>
     /// Determines whether the "grant_type" parameter corresponds to the authorization code grant.
@@ -420,15 +335,8 @@ public static class OpenIddictExtensions
     /// </summary>
     /// <param name="request">The <see cref="OpenIddictRequest"/> instance.</param>
     /// <returns><c>true</c> if the request is a code grant request, <c>false</c> otherwise.</returns>
-    public static bool IsAuthorizationCodeGrantType(this OpenIddictRequest request)
-    {
-        if (request is null)
-        {
-            throw new ArgumentNullException(nameof(request));
-        }
-
-        return string.Equals(request.GrantType, GrantTypes.AuthorizationCode, StringComparison.Ordinal);
-    }
+    public static bool IsAuthorizationCodeGrantType(this OpenIddictRequest request!!)
+        => string.Equals(request.GrantType, GrantTypes.AuthorizationCode, StringComparison.Ordinal);
 
     /// <summary>
     /// Determines whether the "grant_type" parameter corresponds to the client credentials grant.
@@ -436,15 +344,8 @@ public static class OpenIddictExtensions
     /// </summary>
     /// <param name="request">The <see cref="OpenIddictRequest"/> instance.</param>
     /// <returns><c>true</c> if the request is a client credentials grant request, <c>false</c> otherwise.</returns>
-    public static bool IsClientCredentialsGrantType(this OpenIddictRequest request)
-    {
-        if (request is null)
-        {
-            throw new ArgumentNullException(nameof(request));
-        }
-
-        return string.Equals(request.GrantType, GrantTypes.ClientCredentials, StringComparison.Ordinal);
-    }
+    public static bool IsClientCredentialsGrantType(this OpenIddictRequest request!!)
+        => string.Equals(request.GrantType, GrantTypes.ClientCredentials, StringComparison.Ordinal);
 
     /// <summary>
     /// Determines whether the "grant_type" parameter corresponds to the device code grant.
@@ -452,15 +353,8 @@ public static class OpenIddictExtensions
     /// </summary>
     /// <param name="request">The <see cref="OpenIddictRequest"/> instance.</param>
     /// <returns><c>true</c> if the request is a device code grant request, <c>false</c> otherwise.</returns>
-    public static bool IsDeviceCodeGrantType(this OpenIddictRequest request)
-    {
-        if (request is null)
-        {
-            throw new ArgumentNullException(nameof(request));
-        }
-
-        return string.Equals(request.GrantType, GrantTypes.DeviceCode, StringComparison.Ordinal);
-    }
+    public static bool IsDeviceCodeGrantType(this OpenIddictRequest request!!)
+        => string.Equals(request.GrantType, GrantTypes.DeviceCode, StringComparison.Ordinal);
 
     /// <summary>
     /// Determines whether the "grant_type" parameter corresponds to the password grant.
@@ -468,15 +362,8 @@ public static class OpenIddictExtensions
     /// </summary>
     /// <param name="request">The <see cref="OpenIddictRequest"/> instance.</param>
     /// <returns><c>true</c> if the request is a password grant request, <c>false</c> otherwise.</returns>
-    public static bool IsPasswordGrantType(this OpenIddictRequest request)
-    {
-        if (request is null)
-        {
-            throw new ArgumentNullException(nameof(request));
-        }
-
-        return string.Equals(request.GrantType, GrantTypes.Password, StringComparison.Ordinal);
-    }
+    public static bool IsPasswordGrantType(this OpenIddictRequest request!!)
+        => string.Equals(request.GrantType, GrantTypes.Password, StringComparison.Ordinal);
 
     /// <summary>
     /// Determines whether the "grant_type" parameter corresponds to the refresh token grant.
@@ -484,28 +371,16 @@ public static class OpenIddictExtensions
     /// </summary>
     /// <param name="request">The <see cref="OpenIddictRequest"/> instance.</param>
     /// <returns><c>true</c> if the request is a refresh token grant request, <c>false</c> otherwise.</returns>
-    public static bool IsRefreshTokenGrantType(this OpenIddictRequest request)
-    {
-        if (request is null)
-        {
-            throw new ArgumentNullException(nameof(request));
-        }
-
-        return string.Equals(request.GrantType, GrantTypes.RefreshToken, StringComparison.Ordinal);
-    }
+    public static bool IsRefreshTokenGrantType(this OpenIddictRequest request!!)
+        => string.Equals(request.GrantType, GrantTypes.RefreshToken, StringComparison.Ordinal);
 
     /// <summary>
     /// Gets the destinations associated with a claim.
     /// </summary>
     /// <param name="claim">The <see cref="Claim"/> instance.</param>
     /// <returns>The destinations associated with the claim.</returns>
-    public static ImmutableArray<string> GetDestinations(this Claim claim)
+    public static ImmutableArray<string> GetDestinations(this Claim claim!!)
     {
-        if (claim is null)
-        {
-            throw new ArgumentNullException(nameof(claim));
-        }
-
         claim.Properties.TryGetValue(Properties.Destinations, out string? destinations);
 
         if (string.IsNullOrEmpty(destinations))
@@ -535,13 +410,8 @@ public static class OpenIddictExtensions
     /// </summary>
     /// <param name="claim">The <see cref="Claim"/> instance.</param>
     /// <param name="destination">The required destination.</param>
-    public static bool HasDestination(this Claim claim, string destination)
+    public static bool HasDestination(this Claim claim!!, string destination)
     {
-        if (claim is null)
-        {
-            throw new ArgumentNullException(nameof(claim));
-        }
-
         if (string.IsNullOrEmpty(destination))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0181), nameof(destination));
@@ -573,13 +443,8 @@ public static class OpenIddictExtensions
     /// </summary>
     /// <param name="claim">The <see cref="Claim"/> instance.</param>
     /// <param name="destinations">The destinations.</param>
-    public static Claim SetDestinations(this Claim claim, ImmutableArray<string> destinations)
+    public static Claim SetDestinations(this Claim claim!!, ImmutableArray<string> destinations)
     {
-        if (claim is null)
-        {
-            throw new ArgumentNullException(nameof(claim));
-        }
-
         if (destinations.IsDefaultOrEmpty)
         {
             claim.Properties.Remove(Properties.Destinations);
@@ -587,7 +452,7 @@ public static class OpenIddictExtensions
             return claim;
         }
 
-        if (destinations.Any(destination => string.IsNullOrEmpty(destination)))
+        if (destinations.Any(string.IsNullOrEmpty))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0182), nameof(destinations));
         }
@@ -635,13 +500,8 @@ public static class OpenIddictExtensions
     /// </summary>
     /// <param name="principal">The principal.</param>
     /// <returns>The destinations, returned as a flattened dictionary.</returns>
-    public static ImmutableDictionary<string, string[]> GetDestinations(this ClaimsPrincipal principal)
+    public static ImmutableDictionary<string, string[]> GetDestinations(this ClaimsPrincipal principal!!)
     {
-        if (principal is null)
-        {
-            throw new ArgumentNullException(nameof(principal));
-        }
-
         var builder = ImmutableDictionary.CreateBuilder<string, string[]>(StringComparer.Ordinal);
 
         foreach (var group in principal.Claims.GroupBy(claim => claim.Type))
@@ -673,18 +533,8 @@ public static class OpenIddictExtensions
     /// <param name="principal">The principal.</param>
     /// <param name="destinations">The destinations, as a flattened dictionary.</param>
     /// <returns>The principal.</returns>
-    public static ClaimsPrincipal SetDestinations(this ClaimsPrincipal principal, ImmutableDictionary<string, string[]> destinations)
+    public static ClaimsPrincipal SetDestinations(this ClaimsPrincipal principal!!, ImmutableDictionary<string, string[]> destinations!!)
     {
-        if (principal is null)
-        {
-            throw new ArgumentNullException(nameof(principal));
-        }
-
-        if (destinations is null)
-        {
-            throw new ArgumentNullException(nameof(destinations));
-        }
-
         foreach (var destination in destinations)
         {
             foreach (var claim in principal.Claims.Where(claim => claim.Type == destination.Key))
@@ -704,18 +554,8 @@ public static class OpenIddictExtensions
     /// The delegate filtering the claims: return <c>true</c>
     /// to accept the claim, <c>false</c> to remove it.
     /// </param>
-    public static ClaimsIdentity Clone(this ClaimsIdentity identity, Func<Claim, bool> filter)
+    public static ClaimsIdentity Clone(this ClaimsIdentity identity!!, Func<Claim, bool> filter!!)
     {
-        if (identity is null)
-        {
-            throw new ArgumentNullException(nameof(identity));
-        }
-
-        if (filter is null)
-        {
-            throw new ArgumentNullException(nameof(filter));
-        }
-
         var clone = identity.Clone();
 
         // Note: make sure to call ToList() to avoid modifying
@@ -744,18 +584,8 @@ public static class OpenIddictExtensions
     /// The delegate filtering the claims: return <c>true</c>
     /// to accept the claim, <c>false</c> to remove it.
     /// </param>
-    public static ClaimsPrincipal Clone(this ClaimsPrincipal principal, Func<Claim, bool> filter)
+    public static ClaimsPrincipal Clone(this ClaimsPrincipal principal!!, Func<Claim, bool> filter!!)
     {
-        if (principal is null)
-        {
-            throw new ArgumentNullException(nameof(principal));
-        }
-
-        if (filter is null)
-        {
-            throw new ArgumentNullException(nameof(filter));
-        }
-
         var clone = new ClaimsPrincipal();
 
         foreach (var identity in principal.Identities)
@@ -772,13 +602,8 @@ public static class OpenIddictExtensions
     /// <param name="identity">The identity.</param>
     /// <param name="type">The type associated with the claim.</param>
     /// <param name="value">The value associated with the claim.</param>
-    public static ClaimsIdentity AddClaim(this ClaimsIdentity identity, string type, string value)
+    public static ClaimsIdentity AddClaim(this ClaimsIdentity identity!!, string type, string value)
     {
-        if (identity is null)
-        {
-            throw new ArgumentNullException(nameof(identity));
-        }
-
         if (string.IsNullOrEmpty(type))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0184), nameof(type));
@@ -800,13 +625,8 @@ public static class OpenIddictExtensions
     /// <param name="type">The type associated with the claim.</param>
     /// <param name="value">The value associated with the claim.</param>
     /// <param name="destinations">The destinations associated with the claim.</param>
-    public static ClaimsIdentity AddClaim(this ClaimsIdentity identity, string type, string value, ImmutableArray<string> destinations)
+    public static ClaimsIdentity AddClaim(this ClaimsIdentity identity!!, string type, string value, ImmutableArray<string> destinations)
     {
-        if (identity is null)
-        {
-            throw new ArgumentNullException(nameof(identity));
-        }
-
         if (string.IsNullOrEmpty(type))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0184), nameof(type));
@@ -837,13 +657,8 @@ public static class OpenIddictExtensions
     /// <param name="identity">The identity.</param>
     /// <param name="type">The type associated with the claim.</param>
     /// <returns>The claim value.</returns>
-    public static string? GetClaim(this ClaimsIdentity identity, string type)
+    public static string? GetClaim(this ClaimsIdentity identity!!, string type)
     {
-        if (identity is null)
-        {
-            throw new ArgumentNullException(nameof(identity));
-        }
-
         if (string.IsNullOrEmpty(type))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0184), nameof(type));
@@ -858,13 +673,8 @@ public static class OpenIddictExtensions
     /// <param name="principal">The principal.</param>
     /// <param name="type">The type associated with the claim.</param>
     /// <returns>The claim value.</returns>
-    public static string? GetClaim(this ClaimsPrincipal principal, string type)
+    public static string? GetClaim(this ClaimsPrincipal principal!!, string type)
     {
-        if (principal is null)
-        {
-            throw new ArgumentNullException(nameof(principal));
-        }
-
         if (string.IsNullOrEmpty(type))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0184), nameof(type));
@@ -879,13 +689,8 @@ public static class OpenIddictExtensions
     /// <param name="identity">The identity.</param>
     /// <param name="type">The type associated with the claims.</param>
     /// <returns>The claim values.</returns>
-    public static ImmutableArray<string> GetClaims(this ClaimsIdentity identity, string type)
+    public static ImmutableArray<string> GetClaims(this ClaimsIdentity identity!!, string type)
     {
-        if (identity is null)
-        {
-            throw new ArgumentNullException(nameof(identity));
-        }
-
         if (string.IsNullOrEmpty(type))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0184), nameof(type));
@@ -900,13 +705,8 @@ public static class OpenIddictExtensions
     /// <param name="identity">The claims identity.</param>
     /// <param name="type">The claim type.</param>
     /// <returns><c>true</c> if the identity contains at least one claim of the specified type.</returns>
-    public static bool HasClaim(this ClaimsIdentity identity, string type)
+    public static bool HasClaim(this ClaimsIdentity identity!!, string type)
     {
-        if (identity is null)
-        {
-            throw new ArgumentNullException(nameof(identity));
-        }
-
         if (string.IsNullOrEmpty(type))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0184), nameof(type));
@@ -921,13 +721,8 @@ public static class OpenIddictExtensions
     /// <param name="principal">The principal.</param>
     /// <param name="type">The type associated with the claims.</param>
     /// <returns>The claim values.</returns>
-    public static ImmutableArray<string> GetClaims(this ClaimsPrincipal principal, string type)
+    public static ImmutableArray<string> GetClaims(this ClaimsPrincipal principal!!, string type)
     {
-        if (principal is null)
-        {
-            throw new ArgumentNullException(nameof(principal));
-        }
-
         if (string.IsNullOrEmpty(type))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0184), nameof(type));
@@ -942,13 +737,8 @@ public static class OpenIddictExtensions
     /// <param name="principal">The claims principal.</param>
     /// <param name="type">The claim type.</param>
     /// <returns><c>true</c> if the principal contains at least one claim of the specified type.</returns>
-    public static bool HasClaim(this ClaimsPrincipal principal, string type)
+    public static bool HasClaim(this ClaimsPrincipal principal!!, string type)
     {
-        if (principal is null)
-        {
-            throw new ArgumentNullException(nameof(principal));
-        }
-
         if (string.IsNullOrEmpty(type))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0184), nameof(type));
@@ -963,13 +753,8 @@ public static class OpenIddictExtensions
     /// <param name="identity">The identity.</param>
     /// <param name="type">The type associated with the claims.</param>
     /// <returns>The claims identity.</returns>
-    public static ClaimsIdentity RemoveClaims(this ClaimsIdentity identity, string type)
+    public static ClaimsIdentity RemoveClaims(this ClaimsIdentity identity!!, string type)
     {
-        if (identity is null)
-        {
-            throw new ArgumentNullException(nameof(identity));
-        }
-
         if (string.IsNullOrEmpty(type))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0184), nameof(type));
@@ -989,13 +774,8 @@ public static class OpenIddictExtensions
     /// <param name="principal">The principal.</param>
     /// <param name="type">The type associated with the claims.</param>
     /// <returns>The claims identity.</returns>
-    public static ClaimsPrincipal RemoveClaims(this ClaimsPrincipal principal, string type)
+    public static ClaimsPrincipal RemoveClaims(this ClaimsPrincipal principal!!, string type)
     {
-        if (principal is null)
-        {
-            throw new ArgumentNullException(nameof(principal));
-        }
-
         if (string.IsNullOrEmpty(type))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0184), nameof(type));
@@ -1019,13 +799,8 @@ public static class OpenIddictExtensions
     /// <param name="type">The type associated with the claims.</param>
     /// <param name="value">The claim value.</param>
     /// <returns>The claims identity.</returns>
-    public static ClaimsIdentity SetClaims(this ClaimsIdentity identity, string type, string? value)
+    public static ClaimsIdentity SetClaims(this ClaimsIdentity identity!!, string type, string? value)
     {
-        if (identity is null)
-        {
-            throw new ArgumentNullException(nameof(identity));
-        }
-
         if (string.IsNullOrEmpty(type))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0184), nameof(type));
@@ -1048,13 +823,8 @@ public static class OpenIddictExtensions
     /// <param name="type">The type associated with the claims.</param>
     /// <param name="value">The claim value.</param>
     /// <returns>The claims identity.</returns>
-    public static ClaimsPrincipal SetClaim(this ClaimsPrincipal principal, string type, string? value)
+    public static ClaimsPrincipal SetClaim(this ClaimsPrincipal principal!!, string type, string? value)
     {
-        if (principal is null)
-        {
-            throw new ArgumentNullException(nameof(principal));
-        }
-
         if (principal.Identity is not ClaimsIdentity identity)
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0286), nameof(principal));
@@ -1082,13 +852,8 @@ public static class OpenIddictExtensions
     /// <param name="type">The type associated with the claims.</param>
     /// <param name="values">The claim values.</param>
     /// <returns>The claims identity.</returns>
-    public static ClaimsIdentity SetClaims(this ClaimsIdentity identity, string type, ImmutableArray<string> values)
+    public static ClaimsIdentity SetClaims(this ClaimsIdentity identity!!, string type, ImmutableArray<string> values)
     {
-        if (identity is null)
-        {
-            throw new ArgumentNullException(nameof(identity));
-        }
-
         if (string.IsNullOrEmpty(type))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0184), nameof(type));
@@ -1111,13 +876,8 @@ public static class OpenIddictExtensions
     /// <param name="type">The type associated with the claims.</param>
     /// <param name="values">The claim values.</param>
     /// <returns>The claims identity.</returns>
-    public static ClaimsPrincipal SetClaims(this ClaimsPrincipal principal, string type, ImmutableArray<string> values)
+    public static ClaimsPrincipal SetClaims(this ClaimsPrincipal principal!!, string type, ImmutableArray<string> values)
     {
-        if (principal is null)
-        {
-            throw new ArgumentNullException(nameof(principal));
-        }
-
         if (principal.Identity is not ClaimsIdentity identity)
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0286), nameof(principal));
@@ -1143,13 +903,8 @@ public static class OpenIddictExtensions
     /// </summary>
     /// <param name="principal">The claims principal.</param>
     /// <returns>The creation date or <c>null</c> if the claim cannot be found.</returns>
-    public static DateTimeOffset? GetCreationDate(this ClaimsPrincipal principal)
+    public static DateTimeOffset? GetCreationDate(this ClaimsPrincipal principal!!)
     {
-        if (principal is null)
-        {
-            throw new ArgumentNullException(nameof(principal));
-        }
-
         var claim = principal.FindFirst(Claims.Private.CreationDate);
         if (claim is null)
         {
@@ -1169,13 +924,8 @@ public static class OpenIddictExtensions
     /// </summary>
     /// <param name="principal">The claims principal.</param>
     /// <returns>The expiration date or <c>null</c> if the claim cannot be found.</returns>
-    public static DateTimeOffset? GetExpirationDate(this ClaimsPrincipal principal)
+    public static DateTimeOffset? GetExpirationDate(this ClaimsPrincipal principal!!)
     {
-        if (principal is null)
-        {
-            throw new ArgumentNullException(nameof(principal));
-        }
-
         var claim = principal.FindFirst(Claims.Private.ExpirationDate);
         if (claim is null)
         {
@@ -1308,13 +1058,8 @@ public static class OpenIddictExtensions
     /// <param name="principal">The claims principal.</param>
     /// <param name="audience">The audience.</param>
     /// <returns><c>true</c> if the principal contains the given audience.</returns>
-    public static bool HasAudience(this ClaimsPrincipal principal, string audience)
+    public static bool HasAudience(this ClaimsPrincipal principal!!, string audience)
     {
-        if (principal is null)
-        {
-            throw new ArgumentNullException(nameof(principal));
-        }
-
         if (string.IsNullOrEmpty(audience))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0186), nameof(audience));
@@ -1329,13 +1074,8 @@ public static class OpenIddictExtensions
     /// <param name="principal">The claims principal.</param>
     /// <param name="presenter">The presenter.</param>
     /// <returns><c>true</c> if the principal contains the given presenter.</returns>
-    public static bool HasPresenter(this ClaimsPrincipal principal, string presenter)
+    public static bool HasPresenter(this ClaimsPrincipal principal!!, string presenter)
     {
-        if (principal is null)
-        {
-            throw new ArgumentNullException(nameof(principal));
-        }
-
         if (string.IsNullOrEmpty(presenter))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0187), nameof(presenter));
@@ -1350,13 +1090,8 @@ public static class OpenIddictExtensions
     /// <param name="principal">The claims principal.</param>
     /// <param name="resource">The resource.</param>
     /// <returns><c>true</c> if the principal contains the given resource.</returns>
-    public static bool HasResource(this ClaimsPrincipal principal, string resource)
+    public static bool HasResource(this ClaimsPrincipal principal!!, string resource)
     {
-        if (principal is null)
-        {
-            throw new ArgumentNullException(nameof(principal));
-        }
-
         if (string.IsNullOrEmpty(resource))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0062), nameof(resource));
@@ -1371,13 +1106,8 @@ public static class OpenIddictExtensions
     /// <param name="principal">The claims principal.</param>
     /// <param name="scope">The scope.</param>
     /// <returns><c>true</c> if the principal contains the given scope.</returns>
-    public static bool HasScope(this ClaimsPrincipal principal, string scope)
+    public static bool HasScope(this ClaimsPrincipal principal!!, string scope)
     {
-        if (principal is null)
-        {
-            throw new ArgumentNullException(nameof(principal));
-        }
-
         if (string.IsNullOrEmpty(scope))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0180), nameof(scope));
@@ -1392,13 +1122,8 @@ public static class OpenIddictExtensions
     /// <param name="principal">The claims principal.</param>
     /// <param name="type">The token type.</param>
     /// <returns><c>true</c> if the token type matches the specified type.</returns>
-    public static bool HasTokenType(this ClaimsPrincipal principal, string type)
+    public static bool HasTokenType(this ClaimsPrincipal principal!!, string type)
     {
-        if (principal is null)
-        {
-            throw new ArgumentNullException(nameof(principal));
-        }
-
         if (string.IsNullOrEmpty(type))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0188), nameof(type));
@@ -1752,13 +1477,8 @@ public static class OpenIddictExtensions
         return false;
     }
 
-    private static TimeSpan? GetLifetime(ClaimsPrincipal principal, string type)
+    private static TimeSpan? GetLifetime(ClaimsPrincipal principal!!, string type)
     {
-        if (principal is null)
-        {
-            throw new ArgumentNullException(nameof(principal));
-        }
-
         var value = principal.GetClaim(type);
         if (string.IsNullOrEmpty(value))
         {

src/OpenIddict.Abstractions/Primitives/OpenIddictMessage.cs

@@ -40,7 +40,7 @@ public class OpenIddictMessage
     /// <remarks>Parameters with a null or empty key are always ignored.</remarks>
     public OpenIddictMessage(JsonElement parameters)
     {
-        if (parameters.ValueKind != JsonValueKind.Object)
+        if (parameters.ValueKind is not JsonValueKind.Object)
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0189), nameof(parameters));
         }
@@ -69,13 +69,8 @@ public class OpenIddictMessage
     /// </summary>
     /// <param name="parameters">The message parameters.</param>
     /// <remarks>Parameters with a null or empty key are always ignored.</remarks>
-    public OpenIddictMessage(IEnumerable<KeyValuePair<string, OpenIddictParameter>> parameters)
+    public OpenIddictMessage(IEnumerable<KeyValuePair<string, OpenIddictParameter>> parameters!!)
     {
-        if (parameters is null)
-        {
-            throw new ArgumentNullException(nameof(parameters));
-        }
-
         foreach (var parameter in parameters)
         {
             // Ignore parameters whose name is null or empty.
@@ -93,13 +88,8 @@ public class OpenIddictMessage
     /// </summary>
     /// <param name="parameters">The message parameters.</param>
     /// <remarks>Parameters with a null or empty key are always ignored.</remarks>
-    public OpenIddictMessage(IEnumerable<KeyValuePair<string, string?>> parameters)
+    public OpenIddictMessage(IEnumerable<KeyValuePair<string, string?>> parameters!!)
     {
-        if (parameters is null)
-        {
-            throw new ArgumentNullException(nameof(parameters));
-        }
-
         foreach (var parameter in parameters.GroupBy(parameter => parameter.Key))
         {
             // Ignore parameters whose name is null or empty.
@@ -128,13 +118,8 @@ public class OpenIddictMessage
     /// </summary>
     /// <param name="parameters">The message parameters.</param>
     /// <remarks>Parameters with a null or empty key are always ignored.</remarks>
-    public OpenIddictMessage(IEnumerable<KeyValuePair<string, string?[]?>> parameters)
+    public OpenIddictMessage(IEnumerable<KeyValuePair<string, string?[]?>> parameters!!)
     {
-        if (parameters is null)
-        {
-            throw new ArgumentNullException(nameof(parameters));
-        }
-
         foreach (var parameter in parameters)
         {
             // Ignore parameters whose name is null or empty.
@@ -161,13 +146,8 @@ public class OpenIddictMessage
     /// </summary>
     /// <param name="parameters">The message parameters.</param>
     /// <remarks>Parameters with a null or empty key are always ignored.</remarks>
-    public OpenIddictMessage(IEnumerable<KeyValuePair<string, StringValues>> parameters)
+    public OpenIddictMessage(IEnumerable<KeyValuePair<string, StringValues>> parameters!!)
     {
-        if (parameters is null)
-        {
-            throw new ArgumentNullException(nameof(parameters));
-        }
-
         foreach (var parameter in parameters)
         {
             // Ignore parameters whose name is null or empty.
@@ -387,13 +367,8 @@ public class OpenIddictMessage
     /// Writes the message to the specified JSON writer.
     /// </summary>
     /// <param name="writer">The UTF-8 JSON writer.</param>
-    public void WriteTo(Utf8JsonWriter writer)
+    public void WriteTo(Utf8JsonWriter writer!!)
     {
-        if (writer is null)
-        {
-            throw new ArgumentNullException(nameof(writer));
-        }
-
         writer.WriteStartObject();
 
         foreach (var parameter in Parameters)

src/OpenIddict.Abstractions/Primitives/OpenIddictParameter.cs

@@ -151,24 +151,24 @@ public readonly struct OpenIddictParameter : IEquatable<OpenIddictParameter>
             switch (left.ValueKind)
             {
                 case JsonValueKind.Undefined:
-                    return right.ValueKind == JsonValueKind.Undefined;
+                    return right.ValueKind is JsonValueKind.Undefined;
 
                 case JsonValueKind.Null:
-                    return right.ValueKind == JsonValueKind.Null;
+                    return right.ValueKind is JsonValueKind.Null;
 
                 case JsonValueKind.False:
-                    return right.ValueKind == JsonValueKind.False;
+                    return right.ValueKind is JsonValueKind.False;
 
                 case JsonValueKind.True:
-                    return right.ValueKind == JsonValueKind.True;
+                    return right.ValueKind is JsonValueKind.True;
 
-                case JsonValueKind.Number when right.ValueKind == JsonValueKind.Number:
+                case JsonValueKind.Number when right.ValueKind is JsonValueKind.Number:
                     return left.GetInt64() == right.GetInt64();
 
-                case JsonValueKind.String when right.ValueKind == JsonValueKind.String:
+                case JsonValueKind.String when right.ValueKind is JsonValueKind.String:
                     return string.Equals(left.GetString(), right.GetString(), StringComparison.Ordinal);
 
-                case JsonValueKind.Array when right.ValueKind == JsonValueKind.Array:
+                case JsonValueKind.Array when right.ValueKind is JsonValueKind.Array:
                     if (left.GetArrayLength() != right.GetArrayLength())
                     {
                         return false;
@@ -187,7 +187,7 @@ public readonly struct OpenIddictParameter : IEquatable<OpenIddictParameter>
 
                     return true;
 
-                case JsonValueKind.Object when right.ValueKind == JsonValueKind.Object:
+                case JsonValueKind.Object when right.ValueKind is JsonValueKind.Object:
                     foreach (var property in left.EnumerateObject())
                     {
                         if (!right.TryGetProperty(property.Name, out JsonElement element) ||
@@ -502,13 +502,8 @@ public readonly struct OpenIddictParameter : IEquatable<OpenIddictParameter>
     /// Writes the parameter value to the specified JSON writer.
     /// </summary>
     /// <param name="writer">The UTF-8 JSON writer.</param>
-    public void WriteTo(Utf8JsonWriter writer)
+    public void WriteTo(Utf8JsonWriter writer!!)
     {
-        if (writer is null)
-        {
-            throw new ArgumentNullException(nameof(writer));
-        }
-
         switch (Value)
         {
             // Note: undefined JsonElement values are assimilated to null values.
@@ -803,7 +798,7 @@ public readonly struct OpenIddictParameter : IEquatable<OpenIddictParameter>
             for (var index = 0; enumerator.MoveNext(); index++)
             {
                 var element = enumerator.Current;
-                if (element.ValueKind != JsonValueKind.String)
+                if (element.ValueKind is not JsonValueKind.String)
                 {
                     return null;
                 }
@@ -820,49 +815,49 @@ public readonly struct OpenIddictParameter : IEquatable<OpenIddictParameter>
     /// </summary>
     /// <param name="value">The value to convert</param>
     /// <returns>An <see cref="OpenIddictParameter"/> instance.</returns>
-    public static implicit operator OpenIddictParameter(bool value) => new OpenIddictParameter(value);
+    public static implicit operator OpenIddictParameter(bool value) => new(value);
 
     /// <summary>
     /// Converts a nullable boolean to an <see cref="OpenIddictParameter"/> instance.
     /// </summary>
     /// <param name="value">The value to convert</param>
     /// <returns>An <see cref="OpenIddictParameter"/> instance.</returns>
-    public static implicit operator OpenIddictParameter(bool? value) => new OpenIddictParameter(value);
+    public static implicit operator OpenIddictParameter(bool? value) => new(value);
 
     /// <summary>
     /// Converts a <see cref="JsonElement"/> to an <see cref="OpenIddictParameter"/> instance.
     /// </summary>
     /// <param name="value">The value to convert</param>
     /// <returns>An <see cref="OpenIddictParameter"/> instance.</returns>
-    public static implicit operator OpenIddictParameter(JsonElement value) => new OpenIddictParameter(value);
+    public static implicit operator OpenIddictParameter(JsonElement value) => new(value);
 
     /// <summary>
     /// Converts a long integer to an <see cref="OpenIddictParameter"/> instance.
     /// </summary>
     /// <param name="value">The value to convert</param>
     /// <returns>An <see cref="OpenIddictParameter"/> instance.</returns>
-    public static implicit operator OpenIddictParameter(long value) => new OpenIddictParameter(value);
+    public static implicit operator OpenIddictParameter(long value) => new(value);
 
     /// <summary>
     /// Converts a nullable long integer to an <see cref="OpenIddictParameter"/> instance.
     /// </summary>
     /// <param name="value">The value to convert</param>
     /// <returns>An <see cref="OpenIddictParameter"/> instance.</returns>
-    public static implicit operator OpenIddictParameter(long? value) => new OpenIddictParameter(value);
+    public static implicit operator OpenIddictParameter(long? value) => new(value);
 
     /// <summary>
     /// Converts a string to an <see cref="OpenIddictParameter"/> instance.
     /// </summary>
     /// <param name="value">The value to convert</param>
     /// <returns>An <see cref="OpenIddictParameter"/> instance.</returns>
-    public static implicit operator OpenIddictParameter(string? value) => new OpenIddictParameter(value);
+    public static implicit operator OpenIddictParameter(string? value) => new(value);
 
     /// <summary>
     /// Converts an array of strings to an <see cref="OpenIddictParameter"/> instance.
     /// </summary>
     /// <param name="value">The value to convert</param>
     /// <returns>An <see cref="OpenIddictParameter"/> instance.</returns>
-    public static implicit operator OpenIddictParameter(string?[]? value) => new OpenIddictParameter(value);
+    public static implicit operator OpenIddictParameter(string?[]? value) => new(value);
 
     /// <summary>
     /// Determines whether a parameter is null or empty.

src/OpenIddict.Client.AspNetCore/OpenIddictClientAspNetCoreBuilder.cs

@@ -20,8 +20,8 @@ public class OpenIddictClientAspNetCoreBuilder
     /// Initializes a new instance of <see cref="OpenIddictClientAspNetCoreBuilder"/>.
     /// </summary>
     /// <param name="services">The services collection.</param>
-    public OpenIddictClientAspNetCoreBuilder(IServiceCollection services)
-        => Services = services ?? throw new ArgumentNullException(nameof(services));
+    public OpenIddictClientAspNetCoreBuilder(IServiceCollection services!!)
+        => Services = services;
 
     /// <summary>
     /// Gets the services collection.
@@ -35,13 +35,8 @@ public class OpenIddictClientAspNetCoreBuilder
     /// <param name="configuration">The delegate used to configure the OpenIddict options.</param>
     /// <remarks>This extension can be safely called multiple times.</remarks>
     /// <returns>The <see cref="OpenIddictClientAspNetCoreBuilder"/>.</returns>
-    public OpenIddictClientAspNetCoreBuilder Configure(Action<OpenIddictClientAspNetCoreOptions> configuration)
+    public OpenIddictClientAspNetCoreBuilder Configure(Action<OpenIddictClientAspNetCoreOptions> configuration!!)
     {
-        if (configuration is null)
-        {
-            throw new ArgumentNullException(nameof(configuration));
-        }
-
         Services.Configure(configuration);
 
         return this;

src/OpenIddict.Client.AspNetCore/OpenIddictClientAspNetCoreConfiguration.cs

@@ -19,13 +19,8 @@ public class OpenIddictClientAspNetCoreConfiguration : IConfigureOptions<Authent
     /// Registers the OpenIddict client handler in the global authentication options.
     /// </summary>
     /// <param name="options">The options instance to initialize.</param>
-    public void Configure(AuthenticationOptions options)
+    public void Configure(AuthenticationOptions options!!)
     {
-        if (options is null)
-        {
-            throw new ArgumentNullException(nameof(options));
-        }
-
         // If a handler was already registered and the type doesn't correspond to the OpenIddict handler, throw an exception.
         if (options.SchemeMap.TryGetValue(OpenIddictClientAspNetCoreDefaults.AuthenticationScheme, out var builder) &&
             builder.HandlerType != typeof(OpenIddictClientAspNetCoreHandler))
@@ -37,13 +32,8 @@ public class OpenIddictClientAspNetCoreConfiguration : IConfigureOptions<Authent
             OpenIddictClientAspNetCoreDefaults.AuthenticationScheme, displayName: null);
     }
 
-    public void Configure(OpenIddictClientOptions options)
+    public void Configure(OpenIddictClientOptions options!!)
     {
-        if (options is null)
-        {
-            throw new ArgumentNullException(nameof(options));
-        }
-
         // Register the built-in event handlers used by the OpenIddict ASP.NET Core client components.
         options.Handlers.AddRange(OpenIddictClientAspNetCoreHandlers.DefaultHandlers);
     }
@@ -53,13 +43,8 @@ public class OpenIddictClientAspNetCoreConfiguration : IConfigureOptions<Authent
     /// </summary>
     /// <param name="name">The authentication scheme associated with the handler instance.</param>
     /// <param name="options">The options instance to initialize.</param>
-    public void PostConfigure(string name, AuthenticationOptions options)
+    public void PostConfigure(string name, AuthenticationOptions options!!)
     {
-        if (options is null)
-        {
-            throw new ArgumentNullException(nameof(options));
-        }
-
         if (!TryValidate(options.SchemeMap, options.DefaultAuthenticateScheme) ||
             !TryValidate(options.SchemeMap, options.DefaultScheme) ||
             !TryValidate(options.SchemeMap, options.DefaultSignInScheme) ||

src/OpenIddict.Client.AspNetCore/OpenIddictClientAspNetCoreExtensions.cs

@@ -22,13 +22,8 @@ public static class OpenIddictClientAspNetCoreExtensions
     /// <param name="builder">The services builder used by OpenIddict to register new services.</param>
     /// <remarks>This extension can be safely called multiple times.</remarks>
     /// <returns>The <see cref="OpenIddictClientAspNetCoreBuilder"/>.</returns>
-    public static OpenIddictClientAspNetCoreBuilder UseAspNetCore(this OpenIddictClientBuilder builder)
+    public static OpenIddictClientAspNetCoreBuilder UseAspNetCore(this OpenIddictClientBuilder builder!!)
     {
-        if (builder is null)
-        {
-            throw new ArgumentNullException(nameof(builder));
-        }
-
         builder.Services.AddAuthentication();
 
         builder.Services.TryAddScoped<OpenIddictClientAspNetCoreHandler>();
@@ -64,18 +59,8 @@ public static class OpenIddictClientAspNetCoreExtensions
     /// <remarks>This extension can be safely called multiple times.</remarks>
     /// <returns>The <see cref="OpenIddictClientBuilder"/>.</returns>
     public static OpenIddictClientBuilder UseAspNetCore(
-        this OpenIddictClientBuilder builder, Action<OpenIddictClientAspNetCoreBuilder> configuration)
+        this OpenIddictClientBuilder builder!!, Action<OpenIddictClientAspNetCoreBuilder> configuration!!)
     {
-        if (builder is null)
-        {
-            throw new ArgumentNullException(nameof(builder));
-        }
-
-        if (configuration is null)
-        {
-            throw new ArgumentNullException(nameof(configuration));
-        }
-
         configuration(builder.UseAspNetCore());
 
         return builder;

src/OpenIddict.Client.AspNetCore/OpenIddictClientAspNetCoreHandler.cs

@@ -27,12 +27,12 @@ public class OpenIddictClientAspNetCoreHandler : AuthenticationHandler<OpenIddic
     /// Creates a new instance of the <see cref="OpenIddictClientAspNetCoreHandler"/> class.
     /// </summary>
     public OpenIddictClientAspNetCoreHandler(
-        IOpenIddictClientDispatcher dispatcher,
-        IOpenIddictClientFactory factory,
-        IOptionsMonitor<OpenIddictClientAspNetCoreOptions> options,
-        ILoggerFactory logger,
-        UrlEncoder encoder,
-        ISystemClock clock)
+        IOpenIddictClientDispatcher dispatcher!!,
+        IOpenIddictClientFactory factory!!,
+        IOptionsMonitor<OpenIddictClientAspNetCoreOptions> options!!,
+        ILoggerFactory logger!!,
+        UrlEncoder encoder!!,
+        ISystemClock clock!!)
         : base(options, logger, encoder, clock)
     {
         _dispatcher = dispatcher;

src/OpenIddict.Client.AspNetCore/OpenIddictClientAspNetCoreHandlerFilters.cs

@@ -24,18 +24,11 @@ public static class OpenIddictClientAspNetCoreHandlerFilters
     {
         private readonly IOptionsMonitor<OpenIddictClientAspNetCoreOptions> _options;
 
-        public RequireRedirectionEndpointPassthroughEnabled(IOptionsMonitor<OpenIddictClientAspNetCoreOptions> options)
+        public RequireRedirectionEndpointPassthroughEnabled(IOptionsMonitor<OpenIddictClientAspNetCoreOptions> options!!)
             => _options = options;
 
-        public ValueTask<bool> IsActiveAsync(BaseContext context)
-        {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-            return new ValueTask<bool>(_options.CurrentValue.EnableRedirectionEndpointPassthrough);
-        }
+        public ValueTask<bool> IsActiveAsync(BaseContext context!!)
+            => new(_options.CurrentValue.EnableRedirectionEndpointPassthrough);
     }
 
     /// <summary>
@@ -45,18 +38,11 @@ public static class OpenIddictClientAspNetCoreHandlerFilters
     {
         private readonly IOptionsMonitor<OpenIddictClientAspNetCoreOptions> _options;
 
-        public RequireErrorPassthroughEnabled(IOptionsMonitor<OpenIddictClientAspNetCoreOptions> options)
+        public RequireErrorPassthroughEnabled(IOptionsMonitor<OpenIddictClientAspNetCoreOptions> options!!)
             => _options = options;
 
-        public ValueTask<bool> IsActiveAsync(BaseContext context)
-        {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-            return new ValueTask<bool>(_options.CurrentValue.EnableErrorPassthrough);
-        }
+        public ValueTask<bool> IsActiveAsync(BaseContext context!!)
+            => new(_options.CurrentValue.EnableErrorPassthrough);
     }
 
     /// <summary>
@@ -64,15 +50,8 @@ public static class OpenIddictClientAspNetCoreHandlerFilters
     /// </summary>
     public class RequireHttpRequest : IOpenIddictClientHandlerFilter<BaseContext>
     {
-        public ValueTask<bool> IsActiveAsync(BaseContext context)
-        {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-            return new ValueTask<bool>(context.Transaction.GetHttpRequest() is not null);
-        }
+        public ValueTask<bool> IsActiveAsync(BaseContext context!!)
+            => new(context.Transaction.GetHttpRequest() is not null);
     }
 
     /// <summary>
@@ -82,17 +61,10 @@ public static class OpenIddictClientAspNetCoreHandlerFilters
     {
         private readonly IOptionsMonitor<OpenIddictClientAspNetCoreOptions> _options;
 
-        public RequireStatusCodePagesIntegrationEnabled(IOptionsMonitor<OpenIddictClientAspNetCoreOptions> options)
+        public RequireStatusCodePagesIntegrationEnabled(IOptionsMonitor<OpenIddictClientAspNetCoreOptions> options!!)
             => _options = options;
 
-        public ValueTask<bool> IsActiveAsync(BaseContext context)
-        {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-            return new ValueTask<bool>(_options.CurrentValue.EnableStatusCodePagesIntegration);
-        }
+        public ValueTask<bool> IsActiveAsync(BaseContext context!!)
+            => new(_options.CurrentValue.EnableStatusCodePagesIntegration);
     }
 }

src/OpenIddict.Client.AspNetCore/OpenIddictClientAspNetCoreHandlers.Authentication.cs

@@ -57,20 +57,12 @@ public static partial class OpenIddictClientAspNetCoreHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public ValueTask HandleAsync(ApplyAuthorizationRequestContext context)
+            public ValueTask HandleAsync(ApplyAuthorizationRequestContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
-
                 // This handler only applies to ASP.NET Core requests. If the HTTP context cannot be resolved,
                 // this may indicate that the request was incorrectly processed by another server stack.
-                var response = context.Transaction.GetHttpRequest()?.HttpContext.Response;
-                if (response is null)
-                {
+                var response = context.Transaction.GetHttpRequest()?.HttpContext.Response ??
                     throw new InvalidOperationException(SR.GetResourceString(SR.ID0114));
-                }
 
                 // Note: while initially not allowed by the core OAuth 2.0 specification, multiple parameters
                 // with the same name are used by derived drafts like the OAuth 2.0 token exchange specification.

src/OpenIddict.Client.AspNetCore/OpenIddictClientAspNetCoreHandlers.cs

@@ -57,20 +57,12 @@ public static partial class OpenIddictClientAspNetCoreHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessRequestContext context)
+        public ValueTask HandleAsync(ProcessRequestContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             // This handler only applies to ASP.NET Core requests. If the HTTP context cannot be resolved,
             // this may indicate that the request was incorrectly processed by another server stack.
-            var request = context.Transaction.GetHttpRequest();
-            if (request is null)
-            {
+            var request = context.Transaction.GetHttpRequest() ??
                 throw new InvalidOperationException(SR.GetResourceString(SR.ID0114));
-            }
 
             context.EndpointType =
                 Matches(request, context.Options.RedirectionEndpointUris) ? OpenIddictClientEndpointType.Redirection :
@@ -149,20 +141,12 @@ public static partial class OpenIddictClientAspNetCoreHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(TContext context)
+        public ValueTask HandleAsync(TContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             // This handler only applies to ASP.NET Core requests. If the HTTP context cannot be resolved,
             // this may indicate that the request was incorrectly processed by another server stack.
-            var request = context.Transaction.GetHttpRequest();
-            if (request is null)
-            {
+            var request = context.Transaction.GetHttpRequest() ??
                 throw new InvalidOperationException(SR.GetResourceString(SR.ID0114));
-            }
 
             if (HttpMethods.IsGet(request.Method))
             {
@@ -203,20 +187,12 @@ public static partial class OpenIddictClientAspNetCoreHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public async ValueTask HandleAsync(TContext context)
+        public async ValueTask HandleAsync(TContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             // This handler only applies to ASP.NET Core requests. If the HTTP context cannot be resolved,
             // this may indicate that the request was incorrectly processed by another server stack.
-            var request = context.Transaction.GetHttpRequest();
-            if (request is null)
-            {
+            var request = context.Transaction.GetHttpRequest() ??
                 throw new InvalidOperationException(SR.GetResourceString(SR.ID0114));
-            }
 
             if (HttpMethods.IsGet(request.Method))
             {
@@ -286,20 +262,12 @@ public static partial class OpenIddictClientAspNetCoreHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public async ValueTask HandleAsync(TContext context)
+        public async ValueTask HandleAsync(TContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             // This handler only applies to ASP.NET Core requests. If the HTTP context cannot be resolved,
             // this may indicate that the request was incorrectly processed by another server stack.
-            var request = context.Transaction.GetHttpRequest();
-            if (request is null)
-            {
+            var request = context.Transaction.GetHttpRequest() ??
                 throw new InvalidOperationException(SR.GetResourceString(SR.ID0114));
-            }
 
             if (HttpMethods.IsPost(request.Method))
             {
@@ -354,7 +322,7 @@ public static partial class OpenIddictClientAspNetCoreHandlers
     {
         private readonly IOptionsMonitor<OpenIddictClientAspNetCoreOptions> _options;
 
-        public ValidateCorrelationCookie(IOptionsMonitor<OpenIddictClientAspNetCoreOptions> options)
+        public ValidateCorrelationCookie(IOptionsMonitor<OpenIddictClientAspNetCoreOptions> options!!)
             => _options = options;
 
         /// <summary>
@@ -370,22 +338,14 @@ public static partial class OpenIddictClientAspNetCoreHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             Debug.Assert(context.StateTokenPrincipal is { Identity: ClaimsIdentity }, SR.GetResourceString(SR.ID4006));
 
             // This handler only applies to ASP.NET Core requests. If the HTTP context cannot be resolved,
             // this may indicate that the request was incorrectly processed by another server stack.
-            var request = context.Transaction.GetHttpRequest();
-            if (request is null)
-            {
+            var request = context.Transaction.GetHttpRequest() ??
                 throw new InvalidOperationException(SR.GetResourceString(SR.ID0114));
-            }
 
             // Resolve the request forgery protection from the state token principal.
             // If the claim cannot be found, this means the protection was disabled
@@ -449,13 +409,8 @@ public static partial class OpenIddictClientAspNetCoreHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessChallengeContext context)
+        public ValueTask HandleAsync(ProcessChallengeContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             var properties = context.Transaction.GetProperty<AuthenticationProperties>(typeof(AuthenticationProperties).FullName!);
             if (properties is null)
             {
@@ -508,7 +463,7 @@ public static partial class OpenIddictClientAspNetCoreHandlers
     {
         private readonly IOptionsMonitor<OpenIddictClientAspNetCoreOptions> _options;
 
-        public GenerateCorrelationCookie(IOptionsMonitor<OpenIddictClientAspNetCoreOptions> options)
+        public GenerateCorrelationCookie(IOptionsMonitor<OpenIddictClientAspNetCoreOptions> options!!)
             => _options = options;
 
         /// <summary>
@@ -524,12 +479,8 @@ public static partial class OpenIddictClientAspNetCoreHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessChallengeContext context)
+        public ValueTask HandleAsync(ProcessChallengeContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
 
             // Note: using a correlation cookie serves as an antiforgery protection as the request will
             // always be rejected if a cookie corresponding to the request forgery protection claim
@@ -548,11 +499,8 @@ public static partial class OpenIddictClientAspNetCoreHandlers
 
             // This handler only applies to ASP.NET Core requests. If the HTTP context cannot be resolved,
             // this may indicate that the request was incorrectly processed by another server stack.
-            var response = context.Transaction.GetHttpRequest()?.HttpContext.Response;
-            if (response is null)
-            {
+            var response = context.Transaction.GetHttpRequest()?.HttpContext.Response ??
                 throw new InvalidOperationException(SR.GetResourceString(SR.ID0114));
-            }
 
             var options = _options.CurrentValue.CookieBuilder.Build(response.HttpContext);
 
@@ -595,13 +543,8 @@ public static partial class OpenIddictClientAspNetCoreHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(TContext context)
+        public ValueTask HandleAsync(TContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             context.SkipRequest();
 
             return default;
@@ -626,20 +569,12 @@ public static partial class OpenIddictClientAspNetCoreHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(TContext context)
+        public ValueTask HandleAsync(TContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             // This handler only applies to ASP.NET Core requests. If the HTTP context cannot be resolved,
             // this may indicate that the request was incorrectly processed by another server stack.
-            var response = context.Transaction.GetHttpRequest()?.HttpContext.Response;
-            if (response is null)
-            {
+            var response = context.Transaction.GetHttpRequest()?.HttpContext.Response ??
                 throw new InvalidOperationException(SR.GetResourceString(SR.ID0114));
-            }
 
             Debug.Assert(context.Transaction.Response is not null, SR.GetResourceString(SR.ID4007));
 
@@ -672,20 +607,12 @@ public static partial class OpenIddictClientAspNetCoreHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(TContext context)
+        public ValueTask HandleAsync(TContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             // This handler only applies to ASP.NET Core requests. If the HTTP context cannot be resolved,
             // this may indicate that the request was incorrectly processed by another server stack.
-            var response = context.Transaction.GetHttpRequest()?.HttpContext.Response;
-            if (response is null)
-            {
+            var response = context.Transaction.GetHttpRequest()?.HttpContext.Response ??
                 throw new InvalidOperationException(SR.GetResourceString(SR.ID0114));
-            }
 
             // Prevent the response from being cached.
             response.Headers[HeaderNames.CacheControl] = "no-store";
@@ -719,20 +646,12 @@ public static partial class OpenIddictClientAspNetCoreHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(TContext context)
+        public ValueTask HandleAsync(TContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             // This handler only applies to ASP.NET Core requests. If the HTTP context cannot be resolved,
             // this may indicate that the request was incorrectly processed by another server stack.
-            var response = context.Transaction.GetHttpRequest()?.HttpContext.Response;
-            if (response is null)
-            {
+            var response = context.Transaction.GetHttpRequest()?.HttpContext.Response ??
                 throw new InvalidOperationException(SR.GetResourceString(SR.ID0114));
-            }
 
             Debug.Assert(context.Transaction.Response is not null, SR.GetResourceString(SR.ID4007));
 
@@ -767,20 +686,12 @@ public static partial class OpenIddictClientAspNetCoreHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(TContext context)
+        public ValueTask HandleAsync(TContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             // This handler only applies to ASP.NET Core requests. If the HTTP context cannot be resolved,
             // this may indicate that the request was incorrectly processed by another server stack.
-            var response = context.Transaction.GetHttpRequest()?.HttpContext.Response;
-            if (response is null)
-            {
+            var response = context.Transaction.GetHttpRequest()?.HttpContext.Response ??
                 throw new InvalidOperationException(SR.GetResourceString(SR.ID0114));
-            }
 
             Debug.Assert(context.Transaction.Response is not null, SR.GetResourceString(SR.ID4007));
 
@@ -826,20 +737,12 @@ public static partial class OpenIddictClientAspNetCoreHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public async ValueTask HandleAsync(TContext context)
+        public async ValueTask HandleAsync(TContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             // This handler only applies to ASP.NET Core requests. If the HTTP context cannot be resolved,
             // this may indicate that the request was incorrectly processed by another server stack.
-            var response = context.Transaction.GetHttpRequest()?.HttpContext.Response;
-            if (response is null)
-            {
+            var response = context.Transaction.GetHttpRequest()?.HttpContext.Response ??
                 throw new InvalidOperationException(SR.GetResourceString(SR.ID0114));
-            }
 
             Debug.Assert(context.Transaction.Response is not null, SR.GetResourceString(SR.ID4007));
 
@@ -903,13 +806,8 @@ public static partial class OpenIddictClientAspNetCoreHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(TContext context)
+        public ValueTask HandleAsync(TContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             context.Logger.LogInformation(SR.GetResourceString(SR.ID6145));
             context.HandleRequest();
 

src/OpenIddict.Client.AspNetCore/OpenIddictClientAspNetCoreHelpers.cs

@@ -19,13 +19,8 @@ public static class OpenIddictClientAspNetCoreHelpers
     /// </summary>
     /// <param name="transaction">The transaction instance.</param>
     /// <returns>The <see cref="HttpRequest"/> instance or <c>null</c> if it couldn't be found.</returns>
-    public static HttpRequest? GetHttpRequest(this OpenIddictClientTransaction transaction)
+    public static HttpRequest? GetHttpRequest(this OpenIddictClientTransaction transaction!!)
     {
-        if (transaction is null)
-        {
-            throw new ArgumentNullException(nameof(transaction));
-        }
-
         if (!transaction.Properties.TryGetValue(typeof(HttpRequest).FullName!, out object? property))
         {
             return null;
@@ -44,13 +39,8 @@ public static class OpenIddictClientAspNetCoreHelpers
     /// </summary>
     /// <param name="context">The context instance.</param>
     /// <returns>The <see cref="OpenIddictClientEndpointType"/>.</returns>
-    public static OpenIddictClientEndpointType GetOpenIddictClientEndpointType(this HttpContext context)
+    public static OpenIddictClientEndpointType GetOpenIddictClientEndpointType(this HttpContext context!!)
     {
-        if (context is null)
-        {
-            throw new ArgumentNullException(nameof(context));
-        }
-
         return context.Features.Get<OpenIddictClientAspNetCoreFeature>()?.Transaction?.EndpointType ?? default;
     }
 
@@ -59,13 +49,8 @@ public static class OpenIddictClientAspNetCoreHelpers
     /// </summary>
     /// <param name="context">The context instance.</param>
     /// <returns>The <see cref="OpenIddictRequest"/> instance or <c>null</c> if it couldn't be found.</returns>
-    public static OpenIddictRequest? GetOpenIddictClientRequest(this HttpContext context)
+    public static OpenIddictRequest? GetOpenIddictClientRequest(this HttpContext context!!)
     {
-        if (context is null)
-        {
-            throw new ArgumentNullException(nameof(context));
-        }
-
         return context.Features.Get<OpenIddictClientAspNetCoreFeature>()?.Transaction?.Request;
     }
 
@@ -74,13 +59,8 @@ public static class OpenIddictClientAspNetCoreHelpers
     /// </summary>
     /// <param name="context">The context instance.</param>
     /// <returns>The <see cref="OpenIddictResponse"/> instance or <c>null</c> if it couldn't be found.</returns>
-    public static OpenIddictResponse? GetOpenIddictClientResponse(this HttpContext context)
+    public static OpenIddictResponse? GetOpenIddictClientResponse(this HttpContext context!!)
     {
-        if (context is null)
-        {
-            throw new ArgumentNullException(nameof(context));
-        }
-
         return context.Features.Get<OpenIddictClientAspNetCoreFeature>()?.Transaction?.Response;
     }
 }

src/OpenIddict.Client.SystemNetHttp/OpenIddictClientSystemNetHttpBuilder.cs

@@ -19,8 +19,8 @@ public class OpenIddictClientSystemNetHttpBuilder
     /// Initializes a new instance of <see cref="OpenIddictClientBuilder"/>.
     /// </summary>
     /// <param name="services">The services collection.</param>
-    public OpenIddictClientSystemNetHttpBuilder(IServiceCollection services)
-        => Services = services ?? throw new ArgumentNullException(nameof(services));
+    public OpenIddictClientSystemNetHttpBuilder(IServiceCollection services!!)
+        => Services = services;
 
     /// <summary>
     /// Gets the services collection.
@@ -34,13 +34,8 @@ public class OpenIddictClientSystemNetHttpBuilder
     /// <param name="configuration">The delegate used to configure the OpenIddict options.</param>
     /// <remarks>This extension can be safely called multiple times.</remarks>
     /// <returns>The <see cref="OpenIddictClientSystemNetHttpBuilder"/>.</returns>
-    public OpenIddictClientSystemNetHttpBuilder Configure(Action<OpenIddictClientSystemNetHttpOptions> configuration)
+    public OpenIddictClientSystemNetHttpBuilder Configure(Action<OpenIddictClientSystemNetHttpOptions> configuration!!)
     {
-        if (configuration is null)
-        {
-            throw new ArgumentNullException(nameof(configuration));
-        }
-
         Services.Configure(configuration);
 
         return this;

src/OpenIddict.Client.SystemNetHttp/OpenIddictClientSystemNetHttpConfiguration.cs

@@ -21,17 +21,12 @@ public class OpenIddictClientSystemNetHttpConfiguration : IConfigureOptions<Open
 #if !SUPPORTS_SERVICE_PROVIDER_IN_HTTP_MESSAGE_HANDLER_BUILDER
     private readonly IServiceProvider _serviceProvider;
 
-    public OpenIddictClientSystemNetHttpConfiguration(IServiceProvider serviceProvider)
+    public OpenIddictClientSystemNetHttpConfiguration(IServiceProvider serviceProvider!!)
         => _serviceProvider = serviceProvider;
 #endif
 
-    public void Configure(OpenIddictClientOptions options)
+    public void Configure(OpenIddictClientOptions options!!)
     {
-        if (options is null)
-        {
-            throw new ArgumentNullException(nameof(options));
-        }
-
         // Register the built-in event handlers used by the OpenIddict System.Net.Http client components.
         options.Handlers.AddRange(OpenIddictClientSystemNetHttpHandlers.DefaultHandlers);
     }
@@ -39,13 +34,8 @@ public class OpenIddictClientSystemNetHttpConfiguration : IConfigureOptions<Open
     public void Configure(HttpClientFactoryOptions options)
         => Debug.Fail("This infrastructure method shouldn't be called.");
 
-    public void Configure(string name, HttpClientFactoryOptions options)
+    public void Configure(string name, HttpClientFactoryOptions options!!)
     {
-        if (options is null)
-        {
-            throw new ArgumentNullException(nameof(options));
-        }
-
         var assembly = typeof(OpenIddictClientSystemNetHttpOptions).Assembly.GetName();
 
         if (!string.Equals(name, assembly.Name, StringComparison.Ordinal))

src/OpenIddict.Client.SystemNetHttp/OpenIddictClientSystemNetHttpExtensions.cs

@@ -23,13 +23,8 @@ public static class OpenIddictClientSystemNetHttpExtensions
     /// <param name="builder">The services builder used by OpenIddict to register new services.</param>
     /// <remarks>This extension can be safely called multiple times.</remarks>
     /// <returns>The <see cref="OpenIddictClientBuilder"/>.</returns>
-    public static OpenIddictClientSystemNetHttpBuilder UseSystemNetHttp(this OpenIddictClientBuilder builder)
+    public static OpenIddictClientSystemNetHttpBuilder UseSystemNetHttp(this OpenIddictClientBuilder builder!!)
     {
-        if (builder is null)
-        {
-            throw new ArgumentNullException(nameof(builder));
-        }
-
         builder.Services.AddHttpClient();
 
         // Register the built-in validation event handlers used by the OpenIddict System.Net.Http components.
@@ -57,18 +52,8 @@ public static class OpenIddictClientSystemNetHttpExtensions
     /// <remarks>This extension can be safely called multiple times.</remarks>
     /// <returns>The <see cref="OpenIddictBuilder"/>.</returns>
     public static OpenIddictClientBuilder UseSystemNetHttp(
-        this OpenIddictClientBuilder builder, Action<OpenIddictClientSystemNetHttpBuilder> configuration)
+        this OpenIddictClientBuilder builder!!, Action<OpenIddictClientSystemNetHttpBuilder> configuration!!)
     {
-        if (builder is null)
-        {
-            throw new ArgumentNullException(nameof(builder));
-        }
-
-        if (configuration is null)
-        {
-            throw new ArgumentNullException(nameof(configuration));
-        }
-
         configuration(builder.UseSystemNetHttp());
 
         return builder;

src/OpenIddict.Client.SystemNetHttp/OpenIddictClientSystemNetHttpHandlerFilters.cs

@@ -16,16 +16,8 @@ public static class OpenIddictClientSystemNetHttpHandlerFilters
     /// </summary>
     public class RequireHttpMetadataAddress : IOpenIddictClientHandlerFilter<BaseExternalContext>
     {
-        public ValueTask<bool> IsActiveAsync(BaseExternalContext context)
-        {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-            return new ValueTask<bool>(
-                string.Equals(context.Address?.Scheme, Uri.UriSchemeHttp, StringComparison.OrdinalIgnoreCase) ||
-                string.Equals(context.Address?.Scheme, Uri.UriSchemeHttps, StringComparison.OrdinalIgnoreCase));
-        }
+        public ValueTask<bool> IsActiveAsync(BaseExternalContext context!!)
+            => new(string.Equals(context.Address?.Scheme, Uri.UriSchemeHttp, StringComparison.OrdinalIgnoreCase) ||
+                   string.Equals(context.Address?.Scheme, Uri.UriSchemeHttps, StringComparison.OrdinalIgnoreCase));
     }
 }

src/OpenIddict.Client.SystemNetHttp/OpenIddictClientSystemNetHttpHandlers.Exchange.cs

@@ -48,22 +48,14 @@ public static partial class OpenIddictClientSystemNetHttpHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public async ValueTask HandleAsync(PrepareTokenRequestContext context)
+            public async ValueTask HandleAsync(PrepareTokenRequestContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
-
                 Debug.Assert(context.Request is not null, SR.GetResourceString(SR.ID4008));
 
                 // This handler only applies to System.Net.Http requests. If the HTTP request cannot be resolved,
                 // this may indicate that the request was incorrectly processed by another client stack.
-                var request = context.Transaction.GetHttpRequestMessage();
-                if (request is null)
-                {
+                var request = context.Transaction.GetHttpRequestMessage() ??
                     throw new InvalidOperationException(SR.GetResourceString(SR.ID0173));
-                }
 
                 // If no client identifier was attached to the request, skip the following logic.
                 if (string.IsNullOrEmpty(context.Request.ClientId))

src/OpenIddict.Client.SystemNetHttp/OpenIddictClientSystemNetHttpHandlers.Userinfo.cs

@@ -48,22 +48,14 @@ public static partial class OpenIddictClientSystemNetHttpHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public ValueTask HandleAsync(PrepareUserinfoRequestContext context)
+            public ValueTask HandleAsync(PrepareUserinfoRequestContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
-
                 Debug.Assert(context.Request is not null, SR.GetResourceString(SR.ID4008));
 
                 // This handler only applies to System.Net.Http requests. If the HTTP request cannot be resolved,
                 // this may indicate that the request was incorrectly processed by another client stack.
-                var request = context.Transaction.GetHttpRequestMessage();
-                if (request is null)
-                {
+                var request = context.Transaction.GetHttpRequestMessage() ??
                     throw new InvalidOperationException(SR.GetResourceString(SR.ID0173));
-                }
 
                 // Attach the authorization header containing the access token to the HTTP request.
                 request.Headers.Authorization = new AuthenticationHeaderValue(Schemes.Bearer, context.Request.AccessToken);
@@ -92,20 +84,12 @@ public static partial class OpenIddictClientSystemNetHttpHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public async ValueTask HandleAsync(ExtractUserinfoResponseContext context)
+            public async ValueTask HandleAsync(ExtractUserinfoResponseContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
-
                 // This handler only applies to System.Net.Http requests. If the HTTP response cannot be resolved,
                 // this may indicate that the request was incorrectly processed by another client stack.
-                var response = context.Transaction.GetHttpResponseMessage();
-                if (response is null)
-                {
+                var response = context.Transaction.GetHttpResponseMessage() ??
                     throw new InvalidOperationException(SR.GetResourceString(SR.ID0173));
-                }
 
                 // The status code is deliberately not validated to ensure even errored responses
                 // (typically in the 4xx range) can be deserialized and handled by the event handlers.

src/OpenIddict.Client.SystemNetHttp/OpenIddictClientSystemNetHttpHandlers.cs

@@ -41,13 +41,8 @@ public static partial class OpenIddictClientSystemNetHttpHandlers
         /// <inheritdoc/>
         [SuppressMessage("Reliability", "CA2000:Dispose objects before losing scope",
             Justification = "The HTTP request message is disposed later by a dedicated handler.")]
-        public ValueTask HandleAsync(TContext context)
+        public ValueTask HandleAsync(TContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             var request = new HttpRequestMessage(HttpMethod.Get, context.Address)
             {
                 Headers =
@@ -83,13 +78,8 @@ public static partial class OpenIddictClientSystemNetHttpHandlers
         /// <inheritdoc/>
         [SuppressMessage("Reliability", "CA2000:Dispose objects before losing scope",
             Justification = "The HTTP request message is disposed later by a dedicated handler.")]
-        public ValueTask HandleAsync(TContext context)
+        public ValueTask HandleAsync(TContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             var request = new HttpRequestMessage(HttpMethod.Post, context.Address)
             {
                 Headers =
@@ -123,22 +113,14 @@ public static partial class OpenIddictClientSystemNetHttpHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(TContext context)
+        public ValueTask HandleAsync(TContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             Debug.Assert(context.Transaction.Request is not null, SR.GetResourceString(SR.ID4008));
 
             // This handler only applies to System.Net.Http requests. If the HTTP request cannot be resolved,
             // this may indicate that the request was incorrectly processed by another client stack.
-            var request = context.Transaction.GetHttpRequestMessage();
-            if (request is null)
-            {
+            var request = context.Transaction.GetHttpRequestMessage() ??
                 throw new InvalidOperationException(SR.GetResourceString(SR.ID0173));
-            }
 
             if (request.RequestUri is null || context.Transaction.Request.Count == 0)
             {
@@ -189,22 +171,14 @@ public static partial class OpenIddictClientSystemNetHttpHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(TContext context)
+        public ValueTask HandleAsync(TContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             Debug.Assert(context.Transaction.Request is not null, SR.GetResourceString(SR.ID4008));
 
             // This handler only applies to System.Net.Http requests. If the HTTP request cannot be resolved,
             // this may indicate that the request was incorrectly processed by another client stack.
-            var request = context.Transaction.GetHttpRequestMessage();
-            if (request is null)
-            {
+            var request = context.Transaction.GetHttpRequestMessage() ??
                 throw new InvalidOperationException(SR.GetResourceString(SR.ID0173));
-            }
 
             request.Content = new FormUrlEncodedContent(
                 from parameter in context.Transaction.Request.GetParameters()
@@ -240,20 +214,12 @@ public static partial class OpenIddictClientSystemNetHttpHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public async ValueTask HandleAsync(TContext context)
+        public async ValueTask HandleAsync(TContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             // This handler only applies to System.Net.Http requests. If the HTTP request cannot be resolved,
             // this may indicate that the request was incorrectly processed by another client stack.
-            var request = context.Transaction.GetHttpRequestMessage();
-            if (request is null)
-            {
+            var request = context.Transaction.GetHttpRequestMessage() ??
                 throw new InvalidOperationException(SR.GetResourceString(SR.ID0173));
-            }
 
             var assembly = typeof(OpenIddictClientSystemNetHttpOptions).Assembly.GetName();
             using var client = _factory.CreateClient(assembly.Name!);
@@ -294,20 +260,12 @@ public static partial class OpenIddictClientSystemNetHttpHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(TContext context)
+        public ValueTask HandleAsync(TContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             // This handler only applies to System.Net.Http requests. If the HTTP request cannot be resolved,
             // this may indicate that the request was incorrectly processed by another client stack.
-            var request = context.Transaction.GetHttpRequestMessage();
-            if (request is null)
-            {
+            var request = context.Transaction.GetHttpRequestMessage() ??
                 throw new InvalidOperationException(SR.GetResourceString(SR.ID0173));
-            }
 
             request.Dispose();
 
@@ -335,20 +293,12 @@ public static partial class OpenIddictClientSystemNetHttpHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public async ValueTask HandleAsync(TContext context)
+        public async ValueTask HandleAsync(TContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             // This handler only applies to System.Net.Http requests. If the HTTP response cannot be resolved,
             // this may indicate that the request was incorrectly processed by another client stack.
-            var response = context.Transaction.GetHttpResponseMessage();
-            if (response is null)
-            {
+            var response = context.Transaction.GetHttpResponseMessage() ??
                 throw new InvalidOperationException(SR.GetResourceString(SR.ID0173));
-            }
 
             // The status code is deliberately not validated to ensure even errored responses
             // (typically in the 4xx range) can be deserialized and handled by the event handlers.
@@ -376,20 +326,12 @@ public static partial class OpenIddictClientSystemNetHttpHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(TContext context)
+        public ValueTask HandleAsync(TContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             // This handler only applies to System.Net.Http requests. If the HTTP response cannot be resolved,
             // this may indicate that the request was incorrectly processed by another client stack.
-            var response = context.Transaction.GetHttpResponseMessage();
-            if (response is null)
-            {
+            var response = context.Transaction.GetHttpResponseMessage() ??
                 throw new InvalidOperationException(SR.GetResourceString(SR.ID0173));
-            }
 
             response.Dispose();
 

src/OpenIddict.Client/OpenIddictClientBuilder.cs

@@ -25,8 +25,8 @@ public class OpenIddictClientBuilder
     /// Initializes a new instance of <see cref="OpenIddictClientBuilder"/>.
     /// </summary>
     /// <param name="services">The services collection.</param>
-    public OpenIddictClientBuilder(IServiceCollection services)
-        => Services = services ?? throw new ArgumentNullException(nameof(services));
+    public OpenIddictClientBuilder(IServiceCollection services!!)
+        => Services = services;
 
     /// <summary>
     /// Gets the services collection.
@@ -42,14 +42,9 @@ public class OpenIddictClientBuilder
     /// <returns>The <see cref="OpenIddictClientBuilder"/>.</returns>
     [EditorBrowsable(EditorBrowsableState.Advanced)]
     public OpenIddictClientBuilder AddEventHandler<TContext>(
-        Action<OpenIddictClientHandlerDescriptor.Builder<TContext>> configuration)
+        Action<OpenIddictClientHandlerDescriptor.Builder<TContext>> configuration!!)
         where TContext : OpenIddictClientEvents.BaseContext
     {
-        if (configuration is null)
-        {
-            throw new ArgumentNullException(nameof(configuration));
-        }
-
         // Note: handlers registered using this API are assumed to be custom handlers by default.
         var builder = OpenIddictClientHandlerDescriptor.CreateBuilder<TContext>()
             .SetType(OpenIddictClientHandlerType.Custom);
@@ -65,13 +60,8 @@ public class OpenIddictClientBuilder
     /// <param name="descriptor">The handler descriptor.</param>
     /// <returns>The <see cref="OpenIddictClientBuilder"/>.</returns>
     [EditorBrowsable(EditorBrowsableState.Advanced)]
-    public OpenIddictClientBuilder AddEventHandler(OpenIddictClientHandlerDescriptor descriptor)
+    public OpenIddictClientBuilder AddEventHandler(OpenIddictClientHandlerDescriptor descriptor!!)
     {
-        if (descriptor is null)
-        {
-            throw new ArgumentNullException(nameof(descriptor));
-        }
-
         // Register the handler in the services collection.
         Services.Add(descriptor.ServiceDescriptor);
 
@@ -84,13 +74,8 @@ public class OpenIddictClientBuilder
     /// <param name="descriptor">The descriptor corresponding to the handler to remove.</param>
     /// <returns>The <see cref="OpenIddictClientBuilder"/>.</returns>
     [EditorBrowsable(EditorBrowsableState.Advanced)]
-    public OpenIddictClientBuilder RemoveEventHandler(OpenIddictClientHandlerDescriptor descriptor)
+    public OpenIddictClientBuilder RemoveEventHandler(OpenIddictClientHandlerDescriptor descriptor!!)
     {
-        if (descriptor is null)
-        {
-            throw new ArgumentNullException(nameof(descriptor));
-        }
-
         Services.RemoveAll(descriptor.ServiceDescriptor.ServiceType);
 
         Services.PostConfigure<OpenIddictClientOptions>(options =>
@@ -113,13 +98,8 @@ public class OpenIddictClientBuilder
     /// <param name="configuration">The delegate used to configure the OpenIddict options.</param>
     /// <remarks>This extension can be safely called multiple times.</remarks>
     /// <returns>The <see cref="OpenIddictClientBuilder"/>.</returns>
-    public OpenIddictClientBuilder Configure(Action<OpenIddictClientOptions> configuration)
+    public OpenIddictClientBuilder Configure(Action<OpenIddictClientOptions> configuration!!)
     {
-        if (configuration is null)
-        {
-            throw new ArgumentNullException(nameof(configuration));
-        }
-
         Services.Configure(configuration);
 
         return this;
@@ -130,28 +110,16 @@ public class OpenIddictClientBuilder
     /// </summary>
     /// <param name="credentials">The encrypting credentials.</param>
     /// <returns>The <see cref="OpenIddictClientBuilder"/>.</returns>
-    public OpenIddictClientBuilder AddEncryptionCredentials(EncryptingCredentials credentials)
-    {
-        if (credentials is null)
-        {
-            throw new ArgumentNullException(nameof(credentials));
-        }
-
-        return Configure(options => options.EncryptionCredentials.Add(credentials));
-    }
+    public OpenIddictClientBuilder AddEncryptionCredentials(EncryptingCredentials credentials!!)
+        => Configure(options => options.EncryptionCredentials.Add(credentials));
 
     /// <summary>
     /// Registers an encryption key.
     /// </summary>
     /// <param name="key">The security key.</param>
     /// <returns>The <see cref="OpenIddictClientBuilder"/>.</returns>
-    public OpenIddictClientBuilder AddEncryptionKey(SecurityKey key)
+    public OpenIddictClientBuilder AddEncryptionKey(SecurityKey key!!)
     {
-        if (key is null)
-        {
-            throw new ArgumentNullException(nameof(key));
-        }
-
         // If the encryption key is an asymmetric security key, ensure it has a private key.
         if (key is AsymmetricSecurityKey asymmetricSecurityKey &&
             asymmetricSecurityKey.PrivateKeyStatus == PrivateKeyStatus.DoesNotExist)
@@ -193,13 +161,8 @@ public class OpenIddictClientBuilder
     /// <returns>The <see cref="OpenIddictClientBuilder"/>.</returns>
     [SuppressMessage("Reliability", "CA2000:Dispose objects before losing scope",
         Justification = "The X.509 certificate is attached to the client options.")]
-    public OpenIddictClientBuilder AddDevelopmentEncryptionCertificate(X500DistinguishedName subject)
+    public OpenIddictClientBuilder AddDevelopmentEncryptionCertificate(X500DistinguishedName subject!!)
     {
-        if (subject is null)
-        {
-            throw new ArgumentNullException(nameof(subject));
-        }
-
         using var store = new X509Store(StoreName.My, StoreLocation.CurrentUser);
         store.Open(OpenFlags.ReadWrite);
 
@@ -354,13 +317,8 @@ public class OpenIddictClientBuilder
     /// </summary>
     /// <param name="certificate">The encryption certificate.</param>
     /// <returns>The <see cref="OpenIddictClientBuilder"/>.</returns>
-    public OpenIddictClientBuilder AddEncryptionCertificate(X509Certificate2 certificate)
+    public OpenIddictClientBuilder AddEncryptionCertificate(X509Certificate2 certificate!!)
     {
-        if (certificate is null)
-        {
-            throw new ArgumentNullException(nameof(certificate));
-        }
-
         // If the certificate is a X.509v3 certificate that specifies at least one
         // key usage, ensure that the certificate key can be used for key encryption.
         if (certificate.Version >= 3)
@@ -406,14 +364,9 @@ public class OpenIddictClientBuilder
     /// <param name="flags">An enumeration of flags indicating how and where to store the private key of the certificate.</param>
     /// <returns>The <see cref="OpenIddictClientBuilder"/>.</returns>
     public OpenIddictClientBuilder AddEncryptionCertificate(
-        Assembly assembly, string resource,
+        Assembly assembly!!, string resource,
         string? password, X509KeyStorageFlags flags)
     {
-        if (assembly is null)
-        {
-            throw new ArgumentNullException(nameof(assembly));
-        }
-
         if (string.IsNullOrEmpty(resource))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0062), nameof(resource));
@@ -456,13 +409,8 @@ public class OpenIddictClientBuilder
     /// <returns>The <see cref="OpenIddictClientBuilder"/>.</returns>
     [SuppressMessage("Reliability", "CA2000:Dispose objects before losing scope",
         Justification = "The X.509 certificate is attached to the client options.")]
-    public OpenIddictClientBuilder AddEncryptionCertificate(Stream stream, string? password, X509KeyStorageFlags flags)
+    public OpenIddictClientBuilder AddEncryptionCertificate(Stream stream!!, string? password, X509KeyStorageFlags flags)
     {
-        if (stream is null)
-        {
-            throw new ArgumentNullException(nameof(stream));
-        }
-
         using var buffer = new MemoryStream();
         stream.CopyTo(buffer);
 
@@ -534,28 +482,16 @@ public class OpenIddictClientBuilder
     /// </summary>
     /// <param name="credentials">The signing credentials.</param>
     /// <returns>The <see cref="OpenIddictClientBuilder"/>.</returns>
-    public OpenIddictClientBuilder AddSigningCredentials(SigningCredentials credentials)
-    {
-        if (credentials is null)
-        {
-            throw new ArgumentNullException(nameof(credentials));
-        }
-
-        return Configure(options => options.SigningCredentials.Add(credentials));
-    }
+    public OpenIddictClientBuilder AddSigningCredentials(SigningCredentials credentials!!)
+        => Configure(options => options.SigningCredentials.Add(credentials));
 
     /// <summary>
     /// Registers a signing key.
     /// </summary>
     /// <param name="key">The security key.</param>
     /// <returns>The <see cref="OpenIddictClientBuilder"/>.</returns>
-    public OpenIddictClientBuilder AddSigningKey(SecurityKey key)
+    public OpenIddictClientBuilder AddSigningKey(SecurityKey key!!)
     {
-        if (key is null)
-        {
-            throw new ArgumentNullException(nameof(key));
-        }
-
         // If the signing key is an asymmetric security key, ensure it has a private key.
         if (key is AsymmetricSecurityKey asymmetricSecurityKey &&
             asymmetricSecurityKey.PrivateKeyStatus == PrivateKeyStatus.DoesNotExist)
@@ -615,13 +551,8 @@ public class OpenIddictClientBuilder
     /// <returns>The <see cref="OpenIddictClientBuilder"/>.</returns>
     [SuppressMessage("Reliability", "CA2000:Dispose objects before losing scope",
         Justification = "The X.509 certificate is attached to the client options.")]
-    public OpenIddictClientBuilder AddDevelopmentSigningCertificate(X500DistinguishedName subject)
+    public OpenIddictClientBuilder AddDevelopmentSigningCertificate(X500DistinguishedName subject!!)
     {
-        if (subject is null)
-        {
-            throw new ArgumentNullException(nameof(subject));
-        }
-
         using var store = new X509Store(StoreName.My, StoreLocation.CurrentUser);
         store.Open(OpenFlags.ReadWrite);
 
@@ -794,13 +725,8 @@ public class OpenIddictClientBuilder
     /// </summary>
     /// <param name="certificate">The signing certificate.</param>
     /// <returns>The <see cref="OpenIddictClientBuilder"/>.</returns>
-    public OpenIddictClientBuilder AddSigningCertificate(X509Certificate2 certificate)
+    public OpenIddictClientBuilder AddSigningCertificate(X509Certificate2 certificate!!)
     {
-        if (certificate is null)
-        {
-            throw new ArgumentNullException(nameof(certificate));
-        }
-
         // If the certificate is a X.509v3 certificate that specifies at least
         // one key usage, ensure that the certificate key can be used for signing.
         if (certificate.Version >= 3)
@@ -846,14 +772,9 @@ public class OpenIddictClientBuilder
     /// <param name="flags">An enumeration of flags indicating how and where to store the private key of the certificate.</param>
     /// <returns>The <see cref="OpenIddictClientBuilder"/>.</returns>
     public OpenIddictClientBuilder AddSigningCertificate(
-        Assembly assembly, string resource,
+        Assembly assembly!!, string resource,
         string? password, X509KeyStorageFlags flags)
     {
-        if (assembly is null)
-        {
-            throw new ArgumentNullException(nameof(assembly));
-        }
-
         if (string.IsNullOrEmpty(resource))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0062), nameof(resource));
@@ -896,13 +817,8 @@ public class OpenIddictClientBuilder
     /// <returns>The <see cref="OpenIddictClientBuilder"/>.</returns>
     [SuppressMessage("Reliability", "CA2000:Dispose objects before losing scope",
         Justification = "The X.509 certificate is attached to the client options.")]
-    public OpenIddictClientBuilder AddSigningCertificate(Stream stream, string? password, X509KeyStorageFlags flags)
+    public OpenIddictClientBuilder AddSigningCertificate(Stream stream!!, string? password, X509KeyStorageFlags flags)
     {
-        if (stream is null)
-        {
-            throw new ArgumentNullException(nameof(stream));
-        }
-
         using var buffer = new MemoryStream();
         stream.CopyTo(buffer);
 
@@ -974,15 +890,8 @@ public class OpenIddictClientBuilder
     /// </summary>
     /// <param name="registration">The client registration.</param>
     /// <returns>The <see cref="OpenIddictClientBuilder"/>.</returns>
-    public OpenIddictClientBuilder AddRegistration(OpenIddictClientRegistration registration)
-    {
-        if (registration is null)
-        {
-            throw new ArgumentNullException(nameof(registration));
-        }
-
-        return Configure(options => options.Registrations.Add(registration));
-    }
+    public OpenIddictClientBuilder AddRegistration(OpenIddictClientRegistration registration!!)
+        => Configure(options => options.Registrations.Add(registration));
 
     /// <summary>
     /// Sets the relative or absolute URLs associated to the redirection endpoint.
@@ -991,15 +900,8 @@ public class OpenIddictClientBuilder
     /// </summary>
     /// <param name="addresses">The addresses associated to the endpoint.</param>
     /// <returns>The <see cref="OpenIddictClientBuilder"/>.</returns>
-    public OpenIddictClientBuilder SetRedirectionEndpointUris(params string[] addresses)
-    {
-        if (addresses is null)
-        {
-            throw new ArgumentNullException(nameof(addresses));
-        }
-
-        return SetRedirectionEndpointUris(addresses.Select(address => new Uri(address, UriKind.RelativeOrAbsolute)).ToArray());
-    }
+    public OpenIddictClientBuilder SetRedirectionEndpointUris(params string[] addresses!!)
+        => SetRedirectionEndpointUris(addresses.Select(address => new Uri(address, UriKind.RelativeOrAbsolute)).ToArray());
 
     /// <summary>
     /// Sets the relative or absolute URLs associated to the redirection endpoint.
@@ -1008,13 +910,8 @@ public class OpenIddictClientBuilder
     /// </summary>
     /// <param name="addresses">The addresses associated to the endpoint.</param>
     /// <returns>The <see cref="OpenIddictClientBuilder"/>.</returns>
-    public OpenIddictClientBuilder SetRedirectionEndpointUris(params Uri[] addresses)
+    public OpenIddictClientBuilder SetRedirectionEndpointUris(params Uri[] addresses!!)
     {
-        if (addresses is null)
-        {
-            throw new ArgumentNullException(nameof(addresses));
-        }
-
         if (addresses.Any(address => !address.IsWellFormedOriginalString()))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0072), nameof(addresses));

src/OpenIddict.Client/OpenIddictClientConfiguration.cs

@@ -27,13 +27,8 @@ public class OpenIddictClientConfiguration : IPostConfigureOptions<OpenIddictCli
     /// </summary>
     /// <param name="name">The authentication scheme associated with the handler instance.</param>
     /// <param name="options">The options instance to initialize.</param>
-    public void PostConfigure(string name, OpenIddictClientOptions options)
+    public void PostConfigure(string name, OpenIddictClientOptions options!!)
     {
-        if (options is null)
-        {
-            throw new ArgumentNullException(nameof(options));
-        }
-
         if (options.JsonWebTokenHandler is null)
         {
             throw new InvalidOperationException(SR.GetResourceString(SR.ID0075));

src/OpenIddict.Client/OpenIddictClientDispatcher.cs

@@ -19,22 +19,17 @@ public class OpenIddictClientDispatcher : IOpenIddictClientDispatcher
     /// Creates a new instance of the <see cref="OpenIddictClientDispatcher"/> class.
     /// </summary>
     public OpenIddictClientDispatcher(
-        ILogger<OpenIddictClientDispatcher> logger,
-        IOptionsMonitor<OpenIddictClientOptions> options,
-        IServiceProvider provider)
+        ILogger<OpenIddictClientDispatcher> logger!!,
+        IOptionsMonitor<OpenIddictClientOptions> options!!,
+        IServiceProvider provider!!)
     {
         _logger = logger;
         _options = options;
         _provider = provider;
     }
 
-    public async ValueTask DispatchAsync<TContext>(TContext context) where TContext : BaseContext
+    public async ValueTask DispatchAsync<TContext>(TContext context!!) where TContext : BaseContext
     {
-        if (context is null)
-        {
-            throw new ArgumentNullException(nameof(context));
-        }
-
         await foreach (var handler in GetHandlersAsync())
         {
             try

src/OpenIddict.Client/OpenIddictClientEvents.cs

@@ -21,8 +21,8 @@ public static partial class OpenIddictClientEvents
         /// <summary>
         /// Creates a new instance of the <see cref="BaseContext"/> class.
         /// </summary>
-        protected BaseContext(OpenIddictClientTransaction transaction)
-            => Transaction = transaction ?? throw new ArgumentNullException(nameof(transaction));
+        protected BaseContext(OpenIddictClientTransaction transaction!!)
+            => Transaction = transaction;
 
         /// <summary>
         /// Gets the environment associated with the current request being processed.

src/OpenIddict.Client/OpenIddictClientExtensions.cs

@@ -21,13 +21,8 @@ public static class OpenIddictClientExtensions
     /// <param name="builder">The services builder used by OpenIddict to register new services.</param>
     /// <remarks>This extension can be safely called multiple times.</remarks>
     /// <returns>The <see cref="OpenIddictClientBuilder"/>.</returns>
-    public static OpenIddictClientBuilder AddClient(this OpenIddictBuilder builder)
+    public static OpenIddictClientBuilder AddClient(this OpenIddictBuilder builder!!)
     {
-        if (builder is null)
-        {
-            throw new ArgumentNullException(nameof(builder));
-        }
-
         builder.Services.AddLogging();
         builder.Services.AddOptions();
 
@@ -74,18 +69,8 @@ public static class OpenIddictClientExtensions
     /// <param name="configuration">The configuration delegate used to configure the client services.</param>
     /// <remarks>This extension can be safely called multiple times.</remarks>
     /// <returns>The <see cref="OpenIddictBuilder"/>.</returns>
-    public static OpenIddictBuilder AddClient(this OpenIddictBuilder builder, Action<OpenIddictClientBuilder> configuration)
+    public static OpenIddictBuilder AddClient(this OpenIddictBuilder builder!!, Action<OpenIddictClientBuilder> configuration!!)
     {
-        if (builder is null)
-        {
-            throw new ArgumentNullException(nameof(builder));
-        }
-
-        if (configuration is null)
-        {
-            throw new ArgumentNullException(nameof(configuration));
-        }
-
         configuration(builder.AddClient());
 
         return builder;

src/OpenIddict.Client/OpenIddictClientFactory.cs

@@ -18,15 +18,15 @@ public class OpenIddictClientFactory : IOpenIddictClientFactory
     /// Creates a new instance of the <see cref="OpenIddictClientFactory"/> class.
     /// </summary>
     public OpenIddictClientFactory(
-        ILogger<OpenIddictClientDispatcher> logger,
-        IOptionsMonitor<OpenIddictClientOptions> options)
+        ILogger<OpenIddictClientDispatcher> logger!!,
+        IOptionsMonitor<OpenIddictClientOptions> options!!)
     {
         _logger = logger;
         _options = options;
     }
 
     public ValueTask<OpenIddictClientTransaction> CreateTransactionAsync()
-        => new ValueTask<OpenIddictClientTransaction>(new OpenIddictClientTransaction
+        => new(new OpenIddictClientTransaction
         {
             Logger = _logger,
             Options = _options.CurrentValue

src/OpenIddict.Client/OpenIddictClientHandler.cs

@@ -18,8 +18,8 @@ public class OpenIddictClientHandler<TContext> : IOpenIddictClientHandler<TConte
     /// Creates a new event using the specified handler delegate.
     /// </summary>
     /// <param name="handler">The event handler delegate.</param>
-    public OpenIddictClientHandler(Func<TContext, ValueTask> handler)
-        => _handler = handler ?? throw new ArgumentNullException(nameof(handler));
+    public OpenIddictClientHandler(Func<TContext, ValueTask> handler!!)
+        => _handler = handler;
 
     /// <summary>
     /// Processes the event.
@@ -28,6 +28,5 @@ public class OpenIddictClientHandler<TContext> : IOpenIddictClientHandler<TConte
     /// <returns>
     /// A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation.
     /// </returns>
-    public ValueTask HandleAsync(TContext context)
-        => _handler(context ?? throw new ArgumentNullException(nameof(context)));
+    public ValueTask HandleAsync(TContext context!!) => _handler(context);
 }

src/OpenIddict.Client/OpenIddictClientHandlerDescriptor.cs

@@ -72,13 +72,8 @@ public class OpenIddictClientHandlerDescriptor
         /// </summary>
         /// <param name="type">The event handler filter type.</param>
         /// <returns>The builder instance, so that calls can be easily chained.</returns>
-        public Builder<TContext> AddFilter(Type type)
+        public Builder<TContext> AddFilter(Type type!!)
         {
-            if (type is null)
-            {
-                throw new ArgumentNullException(nameof(type));
-            }
-
             if (!typeof(IOpenIddictClientHandlerFilter<>).MakeGenericType(typeof(TContext)).IsAssignableFrom(type))
             {
                 throw new InvalidOperationException(SR.GetResourceString(SR.ID0104));
@@ -104,13 +99,8 @@ public class OpenIddictClientHandlerDescriptor
         /// <param name="descriptor">The existing descriptor properties are copied from.</param>
         /// <remarks>All the properties previously set on this instance are automatically replaced.</remarks>
         /// <returns>The builder instance, so that calls can be easily chained.</returns>
-        public Builder<TContext> Import(OpenIddictClientHandlerDescriptor descriptor)
+        public Builder<TContext> Import(OpenIddictClientHandlerDescriptor descriptor!!)
         {
-            if (descriptor is null)
-            {
-                throw new ArgumentNullException(nameof(descriptor));
-            }
-
             if (descriptor.ContextType != typeof(TContext))
             {
                 throw new InvalidOperationException(SR.GetResourceString(SR.ID0284));
@@ -130,13 +120,8 @@ public class OpenIddictClientHandlerDescriptor
         /// </summary>
         /// <param name="descriptor">The service descriptor.</param>
         /// <returns>The builder instance, so that calls can be easily chained.</returns>
-        public Builder<TContext> SetServiceDescriptor(ServiceDescriptor descriptor)
+        public Builder<TContext> SetServiceDescriptor(ServiceDescriptor descriptor!!)
         {
-            if (descriptor is null)
-            {
-                throw new ArgumentNullException(nameof(descriptor));
-            }
-
             var type = descriptor.ServiceType;
             if (!typeof(IOpenIddictClientHandler<>).MakeGenericType(typeof(TContext)).IsAssignableFrom(type))
             {
@@ -182,15 +167,8 @@ public class OpenIddictClientHandlerDescriptor
         /// </summary>
         /// <param name="handler">The handler instance.</param>
         /// <returns>The builder instance, so that calls can be easily chained.</returns>
-        public Builder<TContext> UseInlineHandler(Func<TContext, ValueTask> handler)
-        {
-            if (handler is null)
-            {
-                throw new ArgumentNullException(nameof(handler));
-            }
-
-            return UseSingletonHandler(new OpenIddictClientHandler<TContext>(handler));
-        }
+        public Builder<TContext> UseInlineHandler(Func<TContext, ValueTask> handler!!)
+            => UseSingletonHandler(new OpenIddictClientHandler<TContext>(handler));
 
         /// <summary>
         /// Configures the descriptor to use the specified scoped handler.
@@ -208,17 +186,10 @@ public class OpenIddictClientHandlerDescriptor
         /// <typeparam name="THandler">The handler type.</typeparam>
         /// <param name="factory">The factory used to create the handler.</param>
         /// <returns>The builder instance, so that calls can be easily chained.</returns>
-        public Builder<TContext> UseScopedHandler<THandler>(Func<IServiceProvider, object> factory)
+        public Builder<TContext> UseScopedHandler<THandler>(Func<IServiceProvider, object> factory!!)
             where THandler : IOpenIddictClientHandler<TContext>
-        {
-            if (factory is null)
-            {
-                throw new ArgumentNullException(nameof(factory));
-            }
-
-            return SetServiceDescriptor(new ServiceDescriptor(
+            => SetServiceDescriptor(new ServiceDescriptor(
                 typeof(THandler), factory, ServiceLifetime.Scoped));
-        }
 
         /// <summary>
         /// Configures the descriptor to use the specified singleton handler.
@@ -236,17 +207,10 @@ public class OpenIddictClientHandlerDescriptor
         /// <typeparam name="THandler">The handler type.</typeparam>
         /// <param name="factory">The factory used to create the handler.</param>
         /// <returns>The builder instance, so that calls can be easily chained.</returns>
-        public Builder<TContext> UseSingletonHandler<THandler>(Func<IServiceProvider, object> factory)
+        public Builder<TContext> UseSingletonHandler<THandler>(Func<IServiceProvider, object> factory!!)
             where THandler : IOpenIddictClientHandler<TContext>
-        {
-            if (factory is null)
-            {
-                throw new ArgumentNullException(nameof(factory));
-            }
-
-            return SetServiceDescriptor(new ServiceDescriptor(
+            => SetServiceDescriptor(new ServiceDescriptor(
                 typeof(THandler), factory, ServiceLifetime.Singleton));
-        }
 
         /// <summary>
         /// Configures the descriptor to use the specified singleton handler.
@@ -254,16 +218,9 @@ public class OpenIddictClientHandlerDescriptor
         /// <typeparam name="THandler">The handler type.</typeparam>
         /// <param name="handler">The handler instance.</param>
         /// <returns>The builder instance, so that calls can be easily chained.</returns>
-        public Builder<TContext> UseSingletonHandler<THandler>(THandler handler)
+        public Builder<TContext> UseSingletonHandler<THandler>(THandler handler!!)
             where THandler : IOpenIddictClientHandler<TContext>
-        {
-            if (handler is null)
-            {
-                throw new ArgumentNullException(nameof(handler));
-            }
-
-            return SetServiceDescriptor(new ServiceDescriptor(typeof(THandler), handler));
-        }
+            => SetServiceDescriptor(new ServiceDescriptor(typeof(THandler), handler));
 
         /// <summary>
         /// Build a new descriptor instance, based on the parameters that were previously set.

src/OpenIddict.Client/OpenIddictClientHandlerFilters.cs

@@ -17,15 +17,8 @@ public static class OpenIddictClientHandlerFilters
     /// </summary>
     public class RequireAuthorizationCodeOrImplicitGrantType : IOpenIddictClientHandlerFilter<ProcessChallengeContext>
     {
-        public ValueTask<bool> IsActiveAsync(ProcessChallengeContext context)
-        {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-            return new ValueTask<bool>(context.GrantType is GrantTypes.AuthorizationCode or GrantTypes.Implicit);
-        }
+        public ValueTask<bool> IsActiveAsync(ProcessChallengeContext context!!)
+            => new(context.GrantType is GrantTypes.AuthorizationCode or GrantTypes.Implicit);
     }
 
     /// <summary>
@@ -33,15 +26,8 @@ public static class OpenIddictClientHandlerFilters
     /// </summary>
     public class RequireAuthorizationCodeValidated : IOpenIddictClientHandlerFilter<ProcessAuthenticationContext>
     {
-        public ValueTask<bool> IsActiveAsync(ProcessAuthenticationContext context)
-        {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-            return new ValueTask<bool>(context.ValidateAuthorizationCode);
-        }
+        public ValueTask<bool> IsActiveAsync(ProcessAuthenticationContext context!!)
+            => new(context.ValidateAuthorizationCode);
     }
 
     /// <summary>
@@ -49,15 +35,8 @@ public static class OpenIddictClientHandlerFilters
     /// </summary>
     public class RequireBackchannelAccessTokenValidated : IOpenIddictClientHandlerFilter<ProcessAuthenticationContext>
     {
-        public ValueTask<bool> IsActiveAsync(ProcessAuthenticationContext context)
-        {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-            return new ValueTask<bool>(context.ValidateBackchannelAccessToken);
-        }
+        public ValueTask<bool> IsActiveAsync(ProcessAuthenticationContext context!!)
+            => new(context.ValidateBackchannelAccessToken);
     }
 
     /// <summary>
@@ -65,15 +44,8 @@ public static class OpenIddictClientHandlerFilters
     /// </summary>
     public class RequireBackchannelIdentityTokenPrincipal : IOpenIddictClientHandlerFilter<ProcessAuthenticationContext>
     {
-        public ValueTask<bool> IsActiveAsync(ProcessAuthenticationContext context)
-        {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-            return new ValueTask<bool>(context.BackchannelIdentityTokenPrincipal is not null);
-        }
+        public ValueTask<bool> IsActiveAsync(ProcessAuthenticationContext context!!)
+            => new(context.BackchannelIdentityTokenPrincipal is not null);
     }
 
     /// <summary>
@@ -81,15 +53,8 @@ public static class OpenIddictClientHandlerFilters
     /// </summary>
     public class RequireBackchannelIdentityTokenValidated : IOpenIddictClientHandlerFilter<ProcessAuthenticationContext>
     {
-        public ValueTask<bool> IsActiveAsync(ProcessAuthenticationContext context)
-        {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-            return new ValueTask<bool>(context.ValidateBackchannelIdentityToken);
-        }
+        public ValueTask<bool> IsActiveAsync(ProcessAuthenticationContext context!!)
+            => new(context.ValidateBackchannelIdentityToken);
     }
 
     /// <summary>
@@ -97,15 +62,8 @@ public static class OpenIddictClientHandlerFilters
     /// </summary>
     public class RequireFrontchannelAccessTokenValidated : IOpenIddictClientHandlerFilter<ProcessAuthenticationContext>
     {
-        public ValueTask<bool> IsActiveAsync(ProcessAuthenticationContext context)
-        {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-            return new ValueTask<bool>(context.ValidateFrontchannelAccessToken);
-        }
+        public ValueTask<bool> IsActiveAsync(ProcessAuthenticationContext context!!)
+            => new(context.ValidateFrontchannelAccessToken);
     }
 
     /// <summary>
@@ -113,15 +71,8 @@ public static class OpenIddictClientHandlerFilters
     /// </summary>
     public class RequireFrontchannelIdentityTokenPrincipal : IOpenIddictClientHandlerFilter<ProcessAuthenticationContext>
     {
-        public ValueTask<bool> IsActiveAsync(ProcessAuthenticationContext context)
-        {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-            return new ValueTask<bool>(context.FrontchannelIdentityTokenPrincipal is not null);
-        }
+        public ValueTask<bool> IsActiveAsync(ProcessAuthenticationContext context!!)
+            => new(context.FrontchannelIdentityTokenPrincipal is not null);
     }
 
     /// <summary>
@@ -129,15 +80,8 @@ public static class OpenIddictClientHandlerFilters
     /// </summary>
     public class RequireFrontchannelIdentityTokenValidated : IOpenIddictClientHandlerFilter<ProcessAuthenticationContext>
     {
-        public ValueTask<bool> IsActiveAsync(ProcessAuthenticationContext context)
-        {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-            return new ValueTask<bool>(context.ValidateFrontchannelIdentityToken);
-        }
+        public ValueTask<bool> IsActiveAsync(ProcessAuthenticationContext context!!)
+            => new(context.ValidateFrontchannelIdentityToken);
     }
 
     /// <summary>
@@ -145,15 +89,8 @@ public static class OpenIddictClientHandlerFilters
     /// </summary>
     public class RequireRedirectionRequest : IOpenIddictClientHandlerFilter<BaseContext>
     {
-        public ValueTask<bool> IsActiveAsync(BaseContext context)
-        {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-            return new ValueTask<bool>(context.EndpointType == OpenIddictClientEndpointType.Redirection);
-        }
+        public ValueTask<bool> IsActiveAsync(BaseContext context!!)
+            => new(context.EndpointType is OpenIddictClientEndpointType.Redirection);
     }
 
     /// <summary>
@@ -161,15 +98,8 @@ public static class OpenIddictClientHandlerFilters
     /// </summary>
     public class RequireRefreshTokenValidated : IOpenIddictClientHandlerFilter<ProcessAuthenticationContext>
     {
-        public ValueTask<bool> IsActiveAsync(ProcessAuthenticationContext context)
-        {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-            return new ValueTask<bool>(context.ValidateRefreshToken);
-        }
+        public ValueTask<bool> IsActiveAsync(ProcessAuthenticationContext context!!)
+            => new(context.ValidateRefreshToken);
     }
 
     /// <summary>
@@ -177,15 +107,8 @@ public static class OpenIddictClientHandlerFilters
     /// </summary>
     public class RequireStateTokenGenerated : IOpenIddictClientHandlerFilter<ProcessChallengeContext>
     {
-        public ValueTask<bool> IsActiveAsync(ProcessChallengeContext context)
-        {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-            return new ValueTask<bool>(context.GenerateStateToken);
-        }
+        public ValueTask<bool> IsActiveAsync(ProcessChallengeContext context!!)
+            => new(context.GenerateStateToken);
     }
 
     /// <summary>
@@ -193,15 +116,8 @@ public static class OpenIddictClientHandlerFilters
     /// </summary>
     public class RequireStateTokenPrincipal : IOpenIddictClientHandlerFilter<ProcessAuthenticationContext>
     {
-        public ValueTask<bool> IsActiveAsync(ProcessAuthenticationContext context)
-        {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-            return new ValueTask<bool>(context.StateTokenPrincipal is not null);
-        }
+        public ValueTask<bool> IsActiveAsync(ProcessAuthenticationContext context!!)
+            => new(context.StateTokenPrincipal is not null);
     }
 
     /// <summary>
@@ -209,15 +125,8 @@ public static class OpenIddictClientHandlerFilters
     /// </summary>
     public class RequireStateTokenValidated : IOpenIddictClientHandlerFilter<ProcessAuthenticationContext>
     {
-        public ValueTask<bool> IsActiveAsync(ProcessAuthenticationContext context)
-        {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-            return new ValueTask<bool>(context.ValidateStateToken);
-        }
+        public ValueTask<bool> IsActiveAsync(ProcessAuthenticationContext context!!)
+            => new(context.ValidateStateToken);
     }
 
     /// <summary>
@@ -225,15 +134,8 @@ public static class OpenIddictClientHandlerFilters
     /// </summary>
     public class RequireTokenRequest : IOpenIddictClientHandlerFilter<ProcessAuthenticationContext>
     {
-        public ValueTask<bool> IsActiveAsync(ProcessAuthenticationContext context)
-        {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-            return new ValueTask<bool>(context.TokenRequest is not null);
-        }
+        public ValueTask<bool> IsActiveAsync(ProcessAuthenticationContext context!!)
+            => new(context.TokenRequest is not null);
     }
 
     /// <summary>
@@ -241,15 +143,8 @@ public static class OpenIddictClientHandlerFilters
     /// </summary>
     public class RequireTokenResponse : IOpenIddictClientHandlerFilter<ProcessAuthenticationContext>
     {
-        public ValueTask<bool> IsActiveAsync(ProcessAuthenticationContext context)
-        {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-            return new ValueTask<bool>(context.TokenResponse is not null);
-        }
+        public ValueTask<bool> IsActiveAsync(ProcessAuthenticationContext context!!)
+            => new(context.TokenResponse is not null);
     }
 
     /// <summary>
@@ -257,15 +152,8 @@ public static class OpenIddictClientHandlerFilters
     /// </summary>
     public class RequireUserinfoRequest : IOpenIddictClientHandlerFilter<ProcessAuthenticationContext>
     {
-        public ValueTask<bool> IsActiveAsync(ProcessAuthenticationContext context)
-        {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-            return new ValueTask<bool>(context.UserinfoRequest is not null);
-        }
+        public ValueTask<bool> IsActiveAsync(ProcessAuthenticationContext context!!)
+            => new(context.UserinfoRequest is not null);
     }
 
     /// <summary>
@@ -273,15 +161,8 @@ public static class OpenIddictClientHandlerFilters
     /// </summary>
     public class RequireUserinfoResponse : IOpenIddictClientHandlerFilter<ProcessAuthenticationContext>
     {
-        public ValueTask<bool> IsActiveAsync(ProcessAuthenticationContext context)
-        {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-            return new ValueTask<bool>(context.UserinfoResponse is not null);
-        }
+        public ValueTask<bool> IsActiveAsync(ProcessAuthenticationContext context!!)
+            => new(context.UserinfoResponse is not null);
     }
 
     /// <summary>
@@ -289,15 +170,8 @@ public static class OpenIddictClientHandlerFilters
     /// </summary>
     public class RequireUserinfoTokenExtracted : IOpenIddictClientHandlerFilter<ProcessAuthenticationContext>
     {
-        public ValueTask<bool> IsActiveAsync(ProcessAuthenticationContext context)
-        {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-            return new ValueTask<bool>(context.ExtractUserinfoToken);
-        }
+        public ValueTask<bool> IsActiveAsync(ProcessAuthenticationContext context!!)
+            => new(context.ExtractUserinfoToken);
     }
 
     /// <summary>
@@ -305,14 +179,7 @@ public static class OpenIddictClientHandlerFilters
     /// </summary>
     public class RequireUserinfoTokenPrincipal : IOpenIddictClientHandlerFilter<ProcessAuthenticationContext>
     {
-        public ValueTask<bool> IsActiveAsync(ProcessAuthenticationContext context)
-        {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-            return new ValueTask<bool>(context.UserinfoTokenPrincipal is not null);
-        }
+        public ValueTask<bool> IsActiveAsync(ProcessAuthenticationContext context!!)
+            => new(context.UserinfoTokenPrincipal is not null);
     }
 }

src/OpenIddict.Client/OpenIddictClientHandlers.Authentication.cs

@@ -51,7 +51,7 @@ public static partial class OpenIddictClientHandlers
         {
             private readonly IOpenIddictClientDispatcher _dispatcher;
 
-            public PrepareAuthorizationRequest(IOpenIddictClientDispatcher dispatcher)
+            public PrepareAuthorizationRequest(IOpenIddictClientDispatcher dispatcher!!)
                 => _dispatcher = dispatcher;
 
             /// <summary>
@@ -65,13 +65,8 @@ public static partial class OpenIddictClientHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public async ValueTask HandleAsync(ProcessChallengeContext context)
+            public async ValueTask HandleAsync(ProcessChallengeContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
-
                 var notification = new PrepareAuthorizationRequestContext(context.Transaction);
                 await _dispatcher.DispatchAsync(notification);
 
@@ -96,7 +91,7 @@ public static partial class OpenIddictClientHandlers
         {
             private readonly IOpenIddictClientDispatcher _dispatcher;
 
-            public ApplyAuthorizationRequest(IOpenIddictClientDispatcher dispatcher)
+            public ApplyAuthorizationRequest(IOpenIddictClientDispatcher dispatcher!!)
                 => _dispatcher = dispatcher;
 
             /// <summary>
@@ -110,13 +105,8 @@ public static partial class OpenIddictClientHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public async ValueTask HandleAsync(ProcessChallengeContext context)
+            public async ValueTask HandleAsync(ProcessChallengeContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
-
                 var notification = new ApplyAuthorizationRequestContext(context.Transaction);
                 await _dispatcher.DispatchAsync(notification);
 
@@ -149,13 +139,8 @@ public static partial class OpenIddictClientHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public async ValueTask HandleAsync(ApplyAuthorizationRequestContext context)
+            public async ValueTask HandleAsync(ApplyAuthorizationRequestContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
-
                 var configuration = await context.Registration.ConfigurationManager.GetConfigurationAsync(default) ??
                     throw new InvalidOperationException(SR.GetResourceString(SR.ID0140));
 
@@ -183,7 +168,7 @@ public static partial class OpenIddictClientHandlers
         {
             private readonly IOpenIddictClientDispatcher _dispatcher;
 
-            public ExtractRedirectionRequest(IOpenIddictClientDispatcher dispatcher)
+            public ExtractRedirectionRequest(IOpenIddictClientDispatcher dispatcher!!)
                 => _dispatcher = dispatcher;
 
             /// <summary>
@@ -197,13 +182,8 @@ public static partial class OpenIddictClientHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public async ValueTask HandleAsync(ProcessRequestContext context)
+            public async ValueTask HandleAsync(ProcessRequestContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
-
                 var notification = new ExtractRedirectionRequestContext(context.Transaction);
                 await _dispatcher.DispatchAsync(notification);
 
@@ -244,7 +224,7 @@ public static partial class OpenIddictClientHandlers
         {
             private readonly IOpenIddictClientDispatcher _dispatcher;
 
-            public ValidateRedirectionRequest(IOpenIddictClientDispatcher dispatcher)
+            public ValidateRedirectionRequest(IOpenIddictClientDispatcher dispatcher!!)
                 => _dispatcher = dispatcher;
 
             /// <summary>
@@ -259,13 +239,8 @@ public static partial class OpenIddictClientHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public async ValueTask HandleAsync(ProcessRequestContext context)
+            public async ValueTask HandleAsync(ProcessRequestContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
-
                 var notification = new ValidateRedirectionRequestContext(context.Transaction);
                 await _dispatcher.DispatchAsync(notification);
 
@@ -301,7 +276,7 @@ public static partial class OpenIddictClientHandlers
         {
             private readonly IOpenIddictClientDispatcher _dispatcher;
 
-            public HandleRedirectionRequest(IOpenIddictClientDispatcher dispatcher)
+            public HandleRedirectionRequest(IOpenIddictClientDispatcher dispatcher!!)
                 => _dispatcher = dispatcher;
 
             /// <summary>
@@ -315,13 +290,8 @@ public static partial class OpenIddictClientHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public async ValueTask HandleAsync(ProcessRequestContext context)
+            public async ValueTask HandleAsync(ProcessRequestContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
-
                 var notification = new HandleRedirectionRequestContext(context.Transaction);
                 await _dispatcher.DispatchAsync(notification);
 
@@ -357,7 +327,7 @@ public static partial class OpenIddictClientHandlers
         {
             private readonly IOpenIddictClientDispatcher _dispatcher;
 
-            public ApplyRedirectionResponse(IOpenIddictClientDispatcher dispatcher)
+            public ApplyRedirectionResponse(IOpenIddictClientDispatcher dispatcher!!)
                 => _dispatcher = dispatcher;
 
             /// <summary>
@@ -372,13 +342,8 @@ public static partial class OpenIddictClientHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public async ValueTask HandleAsync(TContext context)
+            public async ValueTask HandleAsync(TContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
-
                 var notification = new ApplyRedirectionResponseContext(context.Transaction);
                 await _dispatcher.DispatchAsync(notification);
 
@@ -414,12 +379,8 @@ public static partial class OpenIddictClientHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public ValueTask HandleAsync(PrepareAuthorizationRequestContext context)
+            public ValueTask HandleAsync(PrepareAuthorizationRequestContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
 
                 // When the response mode corresponds to the default mode assigned to the selected
                 // response type, the specification explicitly recommends omitting the response mode.
@@ -451,7 +412,7 @@ public static partial class OpenIddictClientHandlers
         {
             private readonly IOpenIddictClientDispatcher _dispatcher;
 
-            public ValidateTokens(IOpenIddictClientDispatcher dispatcher)
+            public ValidateTokens(IOpenIddictClientDispatcher dispatcher!!)
                 => _dispatcher = dispatcher;
 
             /// <summary>
@@ -465,13 +426,8 @@ public static partial class OpenIddictClientHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public async ValueTask HandleAsync(ValidateRedirectionRequestContext context)
+            public async ValueTask HandleAsync(ValidateRedirectionRequestContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
-
                 var notification = new ProcessAuthenticationContext(context.Transaction);
                 await _dispatcher.DispatchAsync(notification);
 

src/OpenIddict.Client/OpenIddictClientHandlers.Discovery.cs

@@ -53,12 +53,8 @@ public static partial class OpenIddictClientHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public ValueTask HandleAsync(HandleConfigurationResponseContext context)
+            public ValueTask HandleAsync(HandleConfigurationResponseContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
 
                 // The issuer returned in the discovery document must exactly match the URL used to access it.
                 // See https://openid.net/specs/openid-connect-discovery-1_0.html#ProviderConfigurationClient.
@@ -105,13 +101,8 @@ public static partial class OpenIddictClientHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public ValueTask HandleAsync(HandleConfigurationResponseContext context)
+            public ValueTask HandleAsync(HandleConfigurationResponseContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
-
                 // Note: the authorization_endpoint node is required by the OpenID Connect discovery specification
                 // but is optional in the OAuth 2.0 authorization server metadata specification. To make OpenIddict
                 // compatible with the newer OAuth 2.0 specification, null/empty and missing values are allowed here.
@@ -157,13 +148,8 @@ public static partial class OpenIddictClientHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public ValueTask HandleAsync(HandleConfigurationResponseContext context)
+            public ValueTask HandleAsync(HandleConfigurationResponseContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
-
                 // Note: the jwks_uri node is required by the OpenID Connect discovery specification.
                 // See https://openid.net/specs/openid-connect-discovery-1_0.html#ProviderConfigurationClient.
                 var address = (string?) context.Response[Metadata.JwksUri];
@@ -209,13 +195,8 @@ public static partial class OpenIddictClientHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public ValueTask HandleAsync(HandleConfigurationResponseContext context)
+            public ValueTask HandleAsync(HandleConfigurationResponseContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
-
                 var address = (string?) context.Response[Metadata.TokenEndpoint];
                 if (!string.IsNullOrEmpty(address))
                 {
@@ -252,13 +233,8 @@ public static partial class OpenIddictClientHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public ValueTask HandleAsync(HandleConfigurationResponseContext context)
+            public ValueTask HandleAsync(HandleConfigurationResponseContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
-
                 var address = (string?) context.Response[Metadata.UserinfoEndpoint];
                 if (!string.IsNullOrEmpty(address))
                 {
@@ -295,12 +271,8 @@ public static partial class OpenIddictClientHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public ValueTask HandleAsync(HandleConfigurationResponseContext context)
+            public ValueTask HandleAsync(HandleConfigurationResponseContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
 
                 // Resolve the grant types supported by the authorization endpoint, if available.
                 var types = context.Response[Metadata.GrantTypesSupported]?.GetUnnamedParameters();
@@ -337,12 +309,8 @@ public static partial class OpenIddictClientHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public ValueTask HandleAsync(HandleConfigurationResponseContext context)
+            public ValueTask HandleAsync(HandleConfigurationResponseContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
 
                 // Resolve the response modes supported by the authorization endpoint, if available.
                 var modes = context.Response[Metadata.ResponseModesSupported]?.GetUnnamedParameters();
@@ -379,12 +347,8 @@ public static partial class OpenIddictClientHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public ValueTask HandleAsync(HandleConfigurationResponseContext context)
+            public ValueTask HandleAsync(HandleConfigurationResponseContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
 
                 // Resolve the response types supported by the authorization endpoint, if available.
                 var types = context.Response[Metadata.ResponseTypesSupported]?.GetUnnamedParameters();
@@ -421,12 +385,8 @@ public static partial class OpenIddictClientHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public ValueTask HandleAsync(HandleConfigurationResponseContext context)
+            public ValueTask HandleAsync(HandleConfigurationResponseContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
 
                 // Resolve the code challenge methods supported by the authorization endpoint, if available.
                 var methods = context.Response[Metadata.CodeChallengeMethodsSupported]?.GetUnnamedParameters();
@@ -463,12 +423,8 @@ public static partial class OpenIddictClientHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public ValueTask HandleAsync(HandleConfigurationResponseContext context)
+            public ValueTask HandleAsync(HandleConfigurationResponseContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
 
                 // Resolve the scopes supported by the remote server, if available.
                 var scopes = context.Response[Metadata.ScopesSupported]?.GetUnnamedParameters();
@@ -506,13 +462,8 @@ public static partial class OpenIddictClientHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public ValueTask HandleAsync(HandleConfigurationResponseContext context)
+            public ValueTask HandleAsync(HandleConfigurationResponseContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
-
                 context.Configuration.AuthorizationResponseIssParameterSupported = (bool?)
                     context.Response[Metadata.AuthorizationResponseIssParameterSupported];
 
@@ -537,12 +488,8 @@ public static partial class OpenIddictClientHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public ValueTask HandleAsync(HandleConfigurationResponseContext context)
+            public ValueTask HandleAsync(HandleConfigurationResponseContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
 
                 // Resolve the client authentication methods supported by the token endpoint, if available.
                 var methods = context.Response[Metadata.TokenEndpointAuthMethodsSupported]?.GetUnnamedParameters();
@@ -579,13 +526,8 @@ public static partial class OpenIddictClientHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public ValueTask HandleAsync(HandleCryptographyResponseContext context)
+            public ValueTask HandleAsync(HandleCryptographyResponseContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
-
                 var keys = context.Response[JsonWebKeySetParameterNames.Keys]?.GetUnnamedParameters();
                 if (keys is not { Count: > 0 })
                 {

src/OpenIddict.Client/OpenIddictClientHandlers.Exchange.cs

@@ -36,13 +36,8 @@ public static partial class OpenIddictClientHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public ValueTask HandleAsync(HandleTokenResponseContext context)
+            public ValueTask HandleAsync(HandleTokenResponseContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
-
                 foreach (var parameter in context.Response.GetParameters())
                 {
                     if (ValidateParameterType(parameter.Key, parameter.Value.Value))

src/OpenIddict.Client/OpenIddictClientHandlers.Protection.cs

@@ -50,12 +50,8 @@ public static partial class OpenIddictClientHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public async ValueTask HandleAsync(ValidateTokenContext context)
+            public async ValueTask HandleAsync(ValidateTokenContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
 
                 // The OpenIddict client is expected to validate tokens it creates (e.g state tokens) and
                 // tokens that are created by one or multiple authorization servers (e.g identity tokens).
@@ -162,13 +158,8 @@ public static partial class OpenIddictClientHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public async ValueTask HandleAsync(ValidateTokenContext context)
+            public async ValueTask HandleAsync(ValidateTokenContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
-
                 // If a principal was already attached, don't overwrite it.
                 if (context.Principal is not null)
                 {
@@ -278,13 +269,8 @@ public static partial class OpenIddictClientHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public ValueTask HandleAsync(ValidateTokenContext context)
+            public ValueTask HandleAsync(ValidateTokenContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
-
                 // Note: only map the private claims from fully trusted tokens.
                 if (context.Principal is null || !context.Principal.HasTokenType(TokenTypeHints.StateToken))
                 {
@@ -335,13 +321,8 @@ public static partial class OpenIddictClientHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public ValueTask HandleAsync(ValidateTokenContext context)
+            public ValueTask HandleAsync(ValidateTokenContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
-
                 if (context.Principal is null)
                 {
                     context.Reject(
@@ -387,13 +368,8 @@ public static partial class OpenIddictClientHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public ValueTask HandleAsync(ValidateTokenContext context)
+            public ValueTask HandleAsync(ValidateTokenContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
-
                 Debug.Assert(context.Principal is { Identity: ClaimsIdentity }, SR.GetResourceString(SR.ID4006));
 
                 var date = context.Principal.GetExpirationDate();
@@ -427,13 +403,8 @@ public static partial class OpenIddictClientHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public ValueTask HandleAsync(GenerateTokenContext context)
+            public ValueTask HandleAsync(GenerateTokenContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
-
                 context.SecurityTokenHandler = context.Options.JsonWebTokenHandler;
 
                 context.EncryptionCredentials = context.Options.EncryptionCredentials.First();
@@ -459,13 +430,8 @@ public static partial class OpenIddictClientHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public ValueTask HandleAsync(GenerateTokenContext context)
+            public ValueTask HandleAsync(GenerateTokenContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
-
                 // If a token was already attached by another handler, don't overwrite it.
                 if (!string.IsNullOrEmpty(context.Token))
                 {

src/OpenIddict.Client/OpenIddictClientHandlers.Userinfo.cs

@@ -40,13 +40,8 @@ public static partial class OpenIddictClientHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public ValueTask HandleAsync(HandleUserinfoResponseContext context)
+            public ValueTask HandleAsync(HandleUserinfoResponseContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
-
                 // Ignore the response instance if a userinfo token was extracted.
                 if (!string.IsNullOrEmpty(context.UserinfoToken))
                 {
@@ -97,13 +92,8 @@ public static partial class OpenIddictClientHandlers
                     .Build();
 
             /// <inheritdoc/>
-            public async ValueTask HandleAsync(HandleUserinfoResponseContext context)
+            public async ValueTask HandleAsync(HandleUserinfoResponseContext context!!)
             {
-                if (context is null)
-                {
-                    throw new ArgumentNullException(nameof(context));
-                }
-
                 // Ignore the response instance if a userinfo token was extracted.
                 if (!string.IsNullOrEmpty(context.UserinfoToken))
                 {

src/OpenIddict.Client/OpenIddictClientHandlers.cs

@@ -124,12 +124,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
 
             // Authentication demands can be triggered from the redirection endpoint
             // to handle authorization callbacks but also from unknown endpoints
@@ -181,13 +177,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             (context.ExtractStateToken,
              context.RequireStateToken,
              context.ValidateStateToken) = context.EndpointType switch
@@ -222,13 +213,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             context.StateToken = context.EndpointType switch
             {
                 OpenIddictClientEndpointType.Redirection when context.ExtractStateToken
@@ -257,13 +243,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             if (context.RequireStateToken && string.IsNullOrEmpty(context.StateToken))
             {
                 context.Reject(
@@ -285,7 +266,7 @@ public static partial class OpenIddictClientHandlers
     {
         private readonly IOpenIddictClientDispatcher _dispatcher;
 
-        public ValidateStateToken(IOpenIddictClientDispatcher dispatcher)
+        public ValidateStateToken(IOpenIddictClientDispatcher dispatcher!!)
             => _dispatcher = dispatcher;
 
         /// <summary>
@@ -300,13 +281,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public async ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public async ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             if (context.StateTokenPrincipal is not null ||
                 string.IsNullOrEmpty(context.StateToken))
             {
@@ -363,13 +339,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             Debug.Assert(context.StateTokenPrincipal is { Identity: ClaimsIdentity }, SR.GetResourceString(SR.ID4006));
 
             // Retrieve the client definition using the authorization server stored in the state token.
@@ -421,13 +392,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public async ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public async ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             Debug.Assert(context.Issuer is { IsAbsoluteUri: true }, SR.GetResourceString(SR.ID4013));
 
             var configuration = await context.Registration.ConfigurationManager.GetConfigurationAsync(default) ??
@@ -512,13 +478,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             var (error, description, uri) = (
                 (string?) context.Request[Parameters.Error],
                 (string?) context.Request[Parameters.ErrorDescription],
@@ -556,13 +517,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             Debug.Assert(context.StateTokenPrincipal is { Identity: ClaimsIdentity }, SR.GetResourceString(SR.ID4006));
 
             // Resolve the negotiated grant type from the state token.
@@ -609,13 +565,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             Debug.Assert(context.StateTokenPrincipal is { Identity: ClaimsIdentity }, SR.GetResourceString(SR.ID4006));
 
             // Resolve the negotiated response type from the state token.
@@ -641,13 +592,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             (context.ExtractAuthorizationCode,
              context.RequireAuthorizationCode,
              context.ValidateAuthorizationCode) = context.GrantType switch
@@ -723,13 +669,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             context.AuthorizationCode = context.EndpointType switch
             {
                 OpenIddictClientEndpointType.Redirection when context.ExtractAuthorizationCode
@@ -774,13 +715,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             if ((context.RequireAuthorizationCode         && string.IsNullOrEmpty(context.AuthorizationCode))       ||
                 (context.RequireFrontchannelAccessToken   && string.IsNullOrEmpty(context.FrontchannelAccessToken)) ||
                 (context.RequireFrontchannelIdentityToken && string.IsNullOrEmpty(context.FrontchannelIdentityToken)))
@@ -804,7 +740,7 @@ public static partial class OpenIddictClientHandlers
     {
         private readonly IOpenIddictClientDispatcher _dispatcher;
 
-        public ValidateFrontchannelIdentityToken(IOpenIddictClientDispatcher dispatcher)
+        public ValidateFrontchannelIdentityToken(IOpenIddictClientDispatcher dispatcher!!)
             => _dispatcher = dispatcher;
 
         /// <summary>
@@ -819,13 +755,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public async ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public async ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             if (context.FrontchannelIdentityTokenPrincipal is not null ||
                 string.IsNullOrEmpty(context.FrontchannelIdentityToken))
             {
@@ -882,13 +813,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             Debug.Assert(context.FrontchannelIdentityTokenPrincipal is { Identity: ClaimsIdentity }, SR.GetResourceString(SR.ID4006));
 
             foreach (var group in context.FrontchannelIdentityTokenPrincipal.Claims
@@ -1018,13 +944,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             Debug.Assert(context.FrontchannelIdentityTokenPrincipal is { Identity: ClaimsIdentity }, SR.GetResourceString(SR.ID4006));
 
             // Note: while an identity token typically contains a single audience represented
@@ -1063,13 +984,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             Debug.Assert(context.FrontchannelIdentityTokenPrincipal is { Identity: ClaimsIdentity }, SR.GetResourceString(SR.ID4006));
 
             // Note: the "azp" claim is optional, but if it's present, it MUST match the client identifier of the application.
@@ -1107,13 +1023,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             Debug.Assert(context.FrontchannelIdentityTokenPrincipal is { Identity: ClaimsIdentity }, SR.GetResourceString(SR.ID4006));
             Debug.Assert(context.StateTokenPrincipal is { Identity: ClaimsIdentity }, SR.GetResourceString(SR.ID4006));
 
@@ -1170,13 +1081,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             Debug.Assert(context.FrontchannelIdentityTokenPrincipal is { Identity: ClaimsIdentity }, SR.GetResourceString(SR.ID4006));
 
             // Resolve the signing algorithm used to sign the identity token. If the private
@@ -1299,7 +1205,7 @@ public static partial class OpenIddictClientHandlers
     {
         private readonly IOpenIddictClientDispatcher _dispatcher;
 
-        public ValidateFrontchannelAccessToken(IOpenIddictClientDispatcher dispatcher)
+        public ValidateFrontchannelAccessToken(IOpenIddictClientDispatcher dispatcher!!)
             => _dispatcher = dispatcher;
 
         /// <summary>
@@ -1314,13 +1220,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public async ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public async ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             if (context.FrontchannelAccessTokenPrincipal is not null ||
                 string.IsNullOrEmpty(context.FrontchannelAccessToken))
             {
@@ -1369,7 +1270,7 @@ public static partial class OpenIddictClientHandlers
     {
         private readonly IOpenIddictClientDispatcher _dispatcher;
 
-        public ValidateAuthorizationCode(IOpenIddictClientDispatcher dispatcher)
+        public ValidateAuthorizationCode(IOpenIddictClientDispatcher dispatcher!!)
             => _dispatcher = dispatcher;
 
         /// <summary>
@@ -1384,13 +1285,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public async ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public async ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             if (context.AuthorizationCodePrincipal is not null ||
                 string.IsNullOrEmpty(context.AuthorizationCode))
             {
@@ -1446,13 +1342,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             (context.ExtractBackchannelAccessToken,
              context.RequireBackchannelAccessToken,
              context.ValidateBackchannelAccessToken) = context.GrantType switch
@@ -1537,13 +1428,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             if (!context.ExtractBackchannelAccessToken   &&
                 !context.ExtractBackchannelIdentityToken &&
                 !context.ExtractRefreshToken)
@@ -1620,13 +1506,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public async ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public async ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             Debug.Assert(context.TokenRequest is not null, SR.GetResourceString(SR.ID4008));
 
             context.TokenResponse = await _service.SendTokenRequestAsync(context.Registration, context.TokenRequest);
@@ -1649,13 +1530,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             Debug.Assert(context.TokenResponse is not null, SR.GetResourceString(SR.ID4007));
 
             if (!string.IsNullOrEmpty(context.TokenResponse.Error))
@@ -1688,13 +1564,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             Debug.Assert(context.TokenResponse is not null, SR.GetResourceString(SR.ID4007));
 
             context.BackchannelAccessToken = context.ExtractBackchannelAccessToken switch
@@ -1735,13 +1606,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             if ((context.RequireBackchannelAccessToken   && string.IsNullOrEmpty(context.BackchannelAccessToken))   ||
                 (context.RequireBackchannelIdentityToken && string.IsNullOrEmpty(context.BackchannelIdentityToken)) ||
                 (context.RequireRefreshToken             && string.IsNullOrEmpty(context.RefreshToken)))
@@ -1765,7 +1631,7 @@ public static partial class OpenIddictClientHandlers
     {
         private readonly IOpenIddictClientDispatcher _dispatcher;
 
-        public ValidateBackchannelIdentityToken(IOpenIddictClientDispatcher dispatcher)
+        public ValidateBackchannelIdentityToken(IOpenIddictClientDispatcher dispatcher!!)
             => _dispatcher = dispatcher;
 
         /// <summary>
@@ -1780,13 +1646,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public async ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public async ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             if (context.BackchannelIdentityTokenPrincipal is not null ||
                 string.IsNullOrEmpty(context.BackchannelIdentityToken))
             {
@@ -1843,13 +1704,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             Debug.Assert(context.BackchannelIdentityTokenPrincipal is { Identity: ClaimsIdentity }, SR.GetResourceString(SR.ID4006));
 
             foreach (var group in context.BackchannelIdentityTokenPrincipal.Claims
@@ -1979,13 +1835,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             Debug.Assert(context.BackchannelIdentityTokenPrincipal is { Identity: ClaimsIdentity }, SR.GetResourceString(SR.ID4006));
 
             // Note: while an identity token typically contains a single audience represented
@@ -2024,13 +1875,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             Debug.Assert(context.BackchannelIdentityTokenPrincipal is { Identity: ClaimsIdentity }, SR.GetResourceString(SR.ID4006));
 
             // Note: the "azp" claim is optional, but if it's present, it MUST match the client identifier of the application.
@@ -2068,13 +1914,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             Debug.Assert(context.BackchannelIdentityTokenPrincipal is { Identity: ClaimsIdentity }, SR.GetResourceString(SR.ID4006));
             Debug.Assert(context.StateTokenPrincipal is { Identity: ClaimsIdentity }, SR.GetResourceString(SR.ID4006));
 
@@ -2131,13 +1972,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             Debug.Assert(context.BackchannelIdentityTokenPrincipal is { Identity: ClaimsIdentity }, SR.GetResourceString(SR.ID4006));
             Debug.Assert(!string.IsNullOrEmpty(context.BackchannelAccessToken), SR.GetResourceString(SR.ID4010));
 
@@ -2233,7 +2069,7 @@ public static partial class OpenIddictClientHandlers
     {
         private readonly IOpenIddictClientDispatcher _dispatcher;
 
-        public ValidateBackchannelAccessToken(IOpenIddictClientDispatcher dispatcher)
+        public ValidateBackchannelAccessToken(IOpenIddictClientDispatcher dispatcher!!)
             => _dispatcher = dispatcher;
 
         /// <summary>
@@ -2248,13 +2084,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public async ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public async ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             if (context.BackchannelAccessTokenPrincipal is not null ||
                 string.IsNullOrEmpty(context.BackchannelAccessToken))
             {
@@ -2303,7 +2134,7 @@ public static partial class OpenIddictClientHandlers
     {
         private readonly IOpenIddictClientDispatcher _dispatcher;
 
-        public ValidateRefreshToken(IOpenIddictClientDispatcher dispatcher)
+        public ValidateRefreshToken(IOpenIddictClientDispatcher dispatcher!!)
             => _dispatcher = dispatcher;
 
         /// <summary>
@@ -2318,13 +2149,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public async ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public async ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             if (context.RefreshTokenPrincipal is not null ||
                 string.IsNullOrEmpty(context.RefreshToken))
             {
@@ -2380,13 +2206,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public async ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public async ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             var configuration = await context.Registration.ConfigurationManager.GetConfigurationAsync(default) ??
                 throw new InvalidOperationException(SR.GetResourceString(SR.ID0140));
 
@@ -2438,12 +2259,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
 
             // Attach a new request instance if necessary.
             context.UserinfoRequest ??= new OpenIddictRequest();
@@ -2486,13 +2303,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public async ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public async ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             Debug.Assert(context.UserinfoRequest is not null, SR.GetResourceString(SR.ID4008));
 
             // Note: userinfo responses can be of two types:
@@ -2520,13 +2332,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             Debug.Assert(context.UserinfoResponse is not null, SR.GetResourceString(SR.ID4007));
 
             if (!string.IsNullOrEmpty(context.UserinfoResponse.Error))
@@ -2559,13 +2366,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             if (context.RequireUserinfoToken && string.IsNullOrEmpty(context.UserinfoToken))
             {
                 context.Reject(
@@ -2587,7 +2389,7 @@ public static partial class OpenIddictClientHandlers
     {
         private readonly IOpenIddictClientDispatcher _dispatcher;
 
-        public ValidateUserinfoToken(IOpenIddictClientDispatcher dispatcher)
+        public ValidateUserinfoToken(IOpenIddictClientDispatcher dispatcher!!)
             => _dispatcher = dispatcher;
 
         /// <summary>
@@ -2602,13 +2404,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public async ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public async ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             if (context.UserinfoTokenPrincipal is not null || string.IsNullOrEmpty(context.UserinfoToken))
             {
                 return;
@@ -2664,13 +2461,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public async ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public async ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             Debug.Assert(context.UserinfoTokenPrincipal is { Identity: ClaimsIdentity }, SR.GetResourceString(SR.ID4006));
 
             var configuration = await context.Registration.ConfigurationManager.GetConfigurationAsync(default) ??
@@ -2737,13 +2529,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public async ValueTask HandleAsync(ProcessAuthenticationContext context)
+        public async ValueTask HandleAsync(ProcessAuthenticationContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             Debug.Assert(context.UserinfoTokenPrincipal is { Identity: ClaimsIdentity }, SR.GetResourceString(SR.ID4006));
 
             var configuration = await context.Registration.ConfigurationManager.GetConfigurationAsync(default) ??
@@ -2822,13 +2609,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessChallengeContext context)
+        public ValueTask HandleAsync(ProcessChallengeContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             // If an explicit grant type was specified, ensure it is supported by OpenIddict.
             if (!string.IsNullOrEmpty(context.GrantType) &&
                 context.GrantType is not (GrantTypes.AuthorizationCode or GrantTypes.Implicit))
@@ -2866,12 +2648,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessChallengeContext context)
+        public ValueTask HandleAsync(ProcessChallengeContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
 
             // Note: if the static registration cannot be found in the options, this may indicate
             // the client was removed after the authorization dance started and thus, can no longer
@@ -2901,13 +2679,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public async ValueTask HandleAsync(ProcessChallengeContext context)
+        public async ValueTask HandleAsync(ProcessChallengeContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             // If an explicit grant type was specified, don't overwrite it.
             if (!string.IsNullOrEmpty(context.GrantType))
             {
@@ -2991,12 +2764,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessChallengeContext context)
+        public ValueTask HandleAsync(ProcessChallengeContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
 
             // In OpenIddict, per-authorization demand values are stored in an encrypted and signed token
             // called "state token", that allows flowing per-authorization demand data like the issuer
@@ -3035,13 +2804,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public async ValueTask HandleAsync(ProcessChallengeContext context)
+        public async ValueTask HandleAsync(ProcessChallengeContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             // If an explicit response type was specified, don't overwrite it.
             if (!string.IsNullOrEmpty(context.ResponseType))
             {
@@ -3233,13 +2997,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public async ValueTask HandleAsync(ProcessChallengeContext context)
+        public async ValueTask HandleAsync(ProcessChallengeContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             // If an explicit response type was specified, don't overwrite it.
             if (!string.IsNullOrEmpty(context.ResponseMode))
             {
@@ -3345,13 +3104,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessChallengeContext context)
+        public ValueTask HandleAsync(ProcessChallengeContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             context.ClientId ??= context.Registration.ClientId;
 
             return default;
@@ -3374,12 +3128,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessChallengeContext context)
+        public ValueTask HandleAsync(ProcessChallengeContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
 
             // Unlike OpenID Connect, OAuth 2.0 and 2.1 don't require specifying a redirect_uri.
             // To keep OpenIddict compatible with OAuth 2.0/2.1 deployments, the redirect_uri
@@ -3407,13 +3157,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public async ValueTask HandleAsync(ProcessChallengeContext context)
+        public async ValueTask HandleAsync(ProcessChallengeContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             // If an explicit set of scopes was specified, don't overwrite it.
             if (context.Scopes.Count > 0)
             {
@@ -3459,12 +3204,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessChallengeContext context)
+        public ValueTask HandleAsync(ProcessChallengeContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
 
             // Generate a new crypto-secure random identifier that will
             // be used as the non-guessable part of the state token.
@@ -3497,13 +3238,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public async ValueTask HandleAsync(ProcessChallengeContext context)
+        public async ValueTask HandleAsync(ProcessChallengeContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             var configuration = await context.Registration.ConfigurationManager.GetConfigurationAsync(default) ??
                 throw new InvalidOperationException(SR.GetResourceString(SR.ID0140));
 
@@ -3547,12 +3283,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public async ValueTask HandleAsync(ProcessChallengeContext context)
+        public async ValueTask HandleAsync(ProcessChallengeContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
 
             // Don't attach a code challenge method if no authorization code is requested as some implementations
             // (like OpenIddict server) are known to eagerly block authorization requests that specify an invalid
@@ -3654,13 +3386,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessChallengeContext context)
+        public ValueTask HandleAsync(ProcessChallengeContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             Debug.Assert(context.Issuer is { IsAbsoluteUri: true }, SR.GetResourceString(SR.ID4013));
             Debug.Assert(context.Principal is { Identity: ClaimsIdentity }, SR.GetResourceString(SR.ID4006));
 
@@ -3751,7 +3478,7 @@ public static partial class OpenIddictClientHandlers
     {
         private readonly IOpenIddictClientDispatcher _dispatcher;
 
-        public GenerateStateToken(IOpenIddictClientDispatcher dispatcher)
+        public GenerateStateToken(IOpenIddictClientDispatcher dispatcher!!)
             => _dispatcher = dispatcher;
 
         /// <summary>
@@ -3766,13 +3493,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public async ValueTask HandleAsync(ProcessChallengeContext context)
+        public async ValueTask HandleAsync(ProcessChallengeContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             var notification = new GenerateTokenContext(context.Transaction)
             {
                 Principal = context.StateTokenPrincipal!,
@@ -3823,12 +3545,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessChallengeContext context)
+        public ValueTask HandleAsync(ProcessChallengeContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
 
             // While OAuth 2.0/2.1 allows sending an authorization request without a redirect_uri,
             // doing so is illegal in OpenID Connect and such requests will always be rejected.
@@ -3858,12 +3576,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessChallengeContext context)
+        public ValueTask HandleAsync(ProcessChallengeContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
 
             // Note: while the exact order of the parameters has typically no effect on how requests
             // are handled by an authorization server, client_id and redirect_uri are deliberately
@@ -3919,13 +3633,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(TContext context)
+        public ValueTask HandleAsync(TContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             if (!string.IsNullOrEmpty(context.Transaction.Response?.Error))
             {
                 context.Reject(
@@ -3956,13 +3665,8 @@ public static partial class OpenIddictClientHandlers
                 .Build();
 
         /// <inheritdoc/>
-        public ValueTask HandleAsync(ProcessErrorContext context)
+        public ValueTask HandleAsync(ProcessErrorContext context!!)
         {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
             context.Response.Error = context.Error;
             context.Response.ErrorDescription = context.ErrorDescription;
             context.Response.ErrorUri = context.ErrorUri;

src/OpenIddict.Client/OpenIddictClientHelpers.cs

@@ -19,13 +19,8 @@ public static class OpenIddictClientHelpers
     /// <param name="name">The property name.</param>
     /// <returns>The property value or <c>null</c> if it couldn't be found.</returns>
     public static TProperty? GetProperty<TProperty>(
-        this OpenIddictClientTransaction transaction, string name) where TProperty : class
+        this OpenIddictClientTransaction transaction!!, string name) where TProperty : class
     {
-        if (transaction is null)
-        {
-            throw new ArgumentNullException(nameof(transaction));
-        }
-
         if (string.IsNullOrEmpty(name))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0106), nameof(name));
@@ -48,14 +43,9 @@ public static class OpenIddictClientHelpers
     /// <param name="value">The property value.</param>
     /// <returns>The client transaction, so that calls can be easily chained.</returns>
     public static OpenIddictClientTransaction SetProperty<TProperty>(
-        this OpenIddictClientTransaction transaction,
+        this OpenIddictClientTransaction transaction!!,
         string name, TProperty? value) where TProperty : class
     {
-        if (transaction is null)
-        {
-            throw new ArgumentNullException(nameof(transaction));
-        }
-
         if (string.IsNullOrEmpty(name))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0106), nameof(name));

src/OpenIddict.Client/OpenIddictClientOptions.cs

@@ -19,7 +19,7 @@ public class OpenIddictClientOptions
     /// Note: the list is automatically sorted based on the order assigned to each handler descriptor.
     /// As such, it MUST NOT be mutated after options initialization to preserve the exact order.
     /// </summary>
-    public List<OpenIddictClientHandlerDescriptor> Handlers { get; } = new(OpenIddictClientHandlers.DefaultHandlers);
+    public List<OpenIddictClientHandlerDescriptor> Handlers { get; } = new(DefaultHandlers);
 
     /// <summary>
     /// Gets the list of encryption credentials used by the OpenIddict client services.

src/OpenIddict.Client/OpenIddictClientRetriever.cs

@@ -16,7 +16,7 @@ public class OpenIddictClientRetriever : IConfigurationRetriever<OpenIddictConfi
     /// Creates a new instance of the <see cref="OpenIddictClientRetriever"/> class.
     /// </summary>
     /// <param name="service">The validation service.</param>
-    public OpenIddictClientRetriever(OpenIddictClientService service)
+    public OpenIddictClientRetriever(OpenIddictClientService service!!)
         => _service = service;
 
     /// <summary>
@@ -26,7 +26,8 @@ public class OpenIddictClientRetriever : IConfigurationRetriever<OpenIddictConfi
     /// <param name="retriever">The retriever used by IdentityModel.</param>
     /// <param name="cancel">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns>The OpenID Connect server configuration retrieved from the remote server.</returns>
-    async Task<OpenIddictConfiguration> IConfigurationRetriever<OpenIddictConfiguration>.GetConfigurationAsync(string address, IDocumentRetriever retriever, CancellationToken cancel)
+    async Task<OpenIddictConfiguration> IConfigurationRetriever<OpenIddictConfiguration>.GetConfigurationAsync(
+        string address, IDocumentRetriever retriever, CancellationToken cancel)
     {
         if (string.IsNullOrEmpty(address))
         {

src/OpenIddict.Client/OpenIddictClientService.cs

@@ -19,7 +19,7 @@ public class OpenIddictClientService
     /// Creates a new instance of the <see cref="OpenIddictClientService"/> class.
     /// </summary>
     /// <param name="provider">The service provider.</param>
-    public OpenIddictClientService(IServiceProvider provider)
+    public OpenIddictClientService(IServiceProvider provider!!)
         => _provider = provider;
 
     /// <summary>
@@ -28,13 +28,8 @@ public class OpenIddictClientService
     /// <param name="address">The address of the remote metadata endpoint.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns>The OpenID Connect server configuration retrieved from the remote server.</returns>
-    public async ValueTask<OpenIddictConfiguration> GetConfigurationAsync(Uri address, CancellationToken cancellationToken = default)
+    public async ValueTask<OpenIddictConfiguration> GetConfigurationAsync(Uri address!!, CancellationToken cancellationToken = default)
     {
-        if (address is null)
-        {
-            throw new ArgumentNullException(nameof(address));
-        }
-
         if (!address.IsAbsoluteUri)
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0144), nameof(address));
@@ -172,13 +167,8 @@ public class OpenIddictClientService
     /// <param name="address">The address of the remote metadata endpoint.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns>The security keys retrieved from the remote server.</returns>
-    public async ValueTask<JsonWebKeySet> GetSecurityKeysAsync(Uri address, CancellationToken cancellationToken = default)
+    public async ValueTask<JsonWebKeySet> GetSecurityKeysAsync(Uri address!!, CancellationToken cancellationToken = default)
     {
-        if (address is null)
-        {
-            throw new ArgumentNullException(nameof(address));
-        }
-
         if (!address.IsAbsoluteUri)
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0144), nameof(address));
@@ -319,13 +309,8 @@ public class OpenIddictClientService
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns>The response and a merged principal containing the claims extracted from the tokens and userinfo response.</returns>
     public async ValueTask<(OpenIddictResponse Response, ClaimsPrincipal Principal)> RefreshTokensAsync(
-        OpenIddictClientRegistration registration, string token, CancellationToken cancellationToken = default)
+        OpenIddictClientRegistration registration!!, string token, CancellationToken cancellationToken = default)
     {
-        if (registration is null)
-        {
-            throw new ArgumentNullException(nameof(registration));
-        }
-
         if (string.IsNullOrEmpty(token))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0156), nameof(token));
@@ -442,13 +427,8 @@ public class OpenIddictClientService
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns>The token response.</returns>
     public async ValueTask<OpenIddictResponse> SendTokenRequestAsync(
-        OpenIddictClientRegistration registration, OpenIddictRequest request, CancellationToken cancellationToken = default)
+        OpenIddictClientRegistration registration!!, OpenIddictRequest request, CancellationToken cancellationToken = default)
     {
-        if (registration is null)
-        {
-            throw new ArgumentNullException(nameof(registration));
-        }
-
         var configuration = await registration.ConfigurationManager.GetConfigurationAsync(default) ??
             throw new InvalidOperationException(SR.GetResourceString(SR.ID0140));
 
@@ -594,13 +574,8 @@ public class OpenIddictClientService
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns>The response and the principal extracted from the userinfo response or the userinfo token.</returns>
     public async ValueTask<(OpenIddictResponse Response, (ClaimsPrincipal? Principal, string? Token))> SendUserinfoRequestAsync(
-        OpenIddictClientRegistration registration, OpenIddictRequest request, CancellationToken cancellationToken = default)
+        OpenIddictClientRegistration registration!!, OpenIddictRequest request, CancellationToken cancellationToken = default)
     {
-        if (registration is null)
-        {
-            throw new ArgumentNullException(nameof(registration));
-        }
-
         var configuration = await registration.ConfigurationManager.GetConfigurationAsync(default) ??
             throw new InvalidOperationException(SR.GetResourceString(SR.ID0140));
 

src/OpenIddict.Core/Caches/OpenIddictApplicationCache.cs

@@ -24,8 +24,8 @@ public class OpenIddictApplicationCache<TApplication> : IOpenIddictApplicationCa
     private readonly IOpenIddictApplicationStore<TApplication> _store;
 
     public OpenIddictApplicationCache(
-        IOptionsMonitor<OpenIddictCoreOptions> options,
-        IOpenIddictApplicationStoreResolver resolver)
+        IOptionsMonitor<OpenIddictCoreOptions> options!!,
+        IOpenIddictApplicationStoreResolver resolver!!)
     {
         _cache = new MemoryCache(new MemoryCacheOptions
         {
@@ -37,13 +37,8 @@ public class OpenIddictApplicationCache<TApplication> : IOpenIddictApplicationCa
     }
 
     /// <inheritdoc/>
-    public async ValueTask AddAsync(TApplication application, CancellationToken cancellationToken)
+    public async ValueTask AddAsync(TApplication application!!, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         _cache.Remove(new
         {
             Method = nameof(FindByClientIdAsync),
@@ -114,10 +109,10 @@ public class OpenIddictApplicationCache<TApplication> : IOpenIddictApplicationCa
 
         if (_cache.TryGetValue(parameters, out TApplication? application))
         {
-            return new ValueTask<TApplication?>(application);
+            return new(application);
         }
 
-        return new ValueTask<TApplication?>(ExecuteAsync());
+        return new(ExecuteAsync());
 
         async Task<TApplication?> ExecuteAsync()
         {
@@ -148,10 +143,10 @@ public class OpenIddictApplicationCache<TApplication> : IOpenIddictApplicationCa
 
         if (_cache.TryGetValue(parameters, out TApplication? application))
         {
-            return new ValueTask<TApplication?>(application);
+            return new(application);
         }
 
-        return new ValueTask<TApplication?>(ExecuteAsync());
+        return new(ExecuteAsync());
 
         async Task<TApplication?> ExecuteAsync()
         {
@@ -249,13 +244,8 @@ public class OpenIddictApplicationCache<TApplication> : IOpenIddictApplicationCa
     }
 
     /// <inheritdoc/>
-    public async ValueTask RemoveAsync(TApplication application, CancellationToken cancellationToken)
+    public async ValueTask RemoveAsync(TApplication application!!, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         var identifier = await _store.GetIdAsync(application, cancellationToken);
         if (string.IsNullOrEmpty(identifier))
         {
@@ -276,13 +266,8 @@ public class OpenIddictApplicationCache<TApplication> : IOpenIddictApplicationCa
     /// <param name="application">The application to store in the cache entry, if applicable.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns>A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation.</returns>
-    protected virtual async ValueTask CreateEntryAsync(object key, TApplication? application, CancellationToken cancellationToken)
+    protected virtual async ValueTask CreateEntryAsync(object key!!, TApplication? application, CancellationToken cancellationToken)
     {
-        if (key is null)
-        {
-            throw new ArgumentNullException(nameof(key));
-        }
-
         using var entry = _cache.CreateEntry(key);
 
         if (application is not null)
@@ -308,13 +293,8 @@ public class OpenIddictApplicationCache<TApplication> : IOpenIddictApplicationCa
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns>A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation.</returns>
     protected virtual async ValueTask CreateEntryAsync(
-        object key, ImmutableArray<TApplication> applications, CancellationToken cancellationToken)
+        object key!!, ImmutableArray<TApplication> applications, CancellationToken cancellationToken)
     {
-        if (key is null)
-        {
-            throw new ArgumentNullException(nameof(key));
-        }
-
         using var entry = _cache.CreateEntry(key);
 
         foreach (var application in applications)
@@ -343,13 +323,8 @@ public class OpenIddictApplicationCache<TApplication> : IOpenIddictApplicationCa
     /// whose result returns an expiration signal for the specified application.
     /// </returns>
     protected virtual async ValueTask<IChangeToken> CreateExpirationSignalAsync(
-        TApplication application, CancellationToken cancellationToken)
+        TApplication application!!, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         var identifier = await _store.GetIdAsync(application, cancellationToken);
         if (string.IsNullOrEmpty(identifier))
         {

src/OpenIddict.Core/Caches/OpenIddictAuthorizationCache.cs

@@ -24,8 +24,8 @@ public class OpenIddictAuthorizationCache<TAuthorization> : IOpenIddictAuthoriza
     private readonly IOpenIddictAuthorizationStore<TAuthorization> _store;
 
     public OpenIddictAuthorizationCache(
-        IOptionsMonitor<OpenIddictCoreOptions> options,
-        IOpenIddictAuthorizationStoreResolver resolver)
+        IOptionsMonitor<OpenIddictCoreOptions> options!!,
+        IOpenIddictAuthorizationStoreResolver resolver!!)
     {
         _cache = new MemoryCache(new MemoryCacheOptions
         {
@@ -37,13 +37,8 @@ public class OpenIddictAuthorizationCache<TAuthorization> : IOpenIddictAuthoriza
     }
 
     /// <inheritdoc/>
-    public async ValueTask AddAsync(TAuthorization authorization, CancellationToken cancellationToken)
+    public async ValueTask AddAsync(TAuthorization authorization!!, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         _cache.Remove(new
         {
             Method = nameof(FindAsync),
@@ -365,10 +360,10 @@ public class OpenIddictAuthorizationCache<TAuthorization> : IOpenIddictAuthoriza
 
         if (_cache.TryGetValue(parameters, out TAuthorization? authorization))
         {
-            return new ValueTask<TAuthorization?>(authorization);
+            return new(authorization);
         }
 
-        return new ValueTask<TAuthorization?>(ExecuteAsync());
+        return new(ExecuteAsync());
 
         async Task<TAuthorization?> ExecuteAsync()
         {
@@ -425,13 +420,8 @@ public class OpenIddictAuthorizationCache<TAuthorization> : IOpenIddictAuthoriza
     }
 
     /// <inheritdoc/>
-    public async ValueTask RemoveAsync(TAuthorization authorization, CancellationToken cancellationToken)
+    public async ValueTask RemoveAsync(TAuthorization authorization!!, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         var identifier = await _store.GetIdAsync(authorization, cancellationToken);
         if (string.IsNullOrEmpty(identifier))
         {
@@ -452,13 +442,8 @@ public class OpenIddictAuthorizationCache<TAuthorization> : IOpenIddictAuthoriza
     /// <param name="authorization">The authorization to store in the cache entry, if applicable.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns>A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation.</returns>
-    protected virtual async ValueTask CreateEntryAsync(object key, TAuthorization? authorization, CancellationToken cancellationToken)
+    protected virtual async ValueTask CreateEntryAsync(object key!!, TAuthorization? authorization, CancellationToken cancellationToken)
     {
-        if (key is null)
-        {
-            throw new ArgumentNullException(nameof(key));
-        }
-
         using var entry = _cache.CreateEntry(key);
 
         if (authorization is not null)
@@ -484,13 +469,8 @@ public class OpenIddictAuthorizationCache<TAuthorization> : IOpenIddictAuthoriza
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns>A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation.</returns>
     protected virtual async ValueTask CreateEntryAsync(
-        object key, ImmutableArray<TAuthorization> authorizations, CancellationToken cancellationToken)
+        object key!!, ImmutableArray<TAuthorization> authorizations, CancellationToken cancellationToken)
     {
-        if (key is null)
-        {
-            throw new ArgumentNullException(nameof(key));
-        }
-
         using var entry = _cache.CreateEntry(key);
 
         foreach (var authorization in authorizations)
@@ -519,13 +499,8 @@ public class OpenIddictAuthorizationCache<TAuthorization> : IOpenIddictAuthoriza
     /// whose result returns an expiration signal for the specified authorization.
     /// </returns>
     protected virtual async ValueTask<IChangeToken> CreateExpirationSignalAsync(
-        TAuthorization authorization, CancellationToken cancellationToken)
+        TAuthorization authorization!!, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         var identifier = await _store.GetIdAsync(authorization, cancellationToken);
         if (string.IsNullOrEmpty(identifier))
         {

src/OpenIddict.Core/Caches/OpenIddictScopeCache.cs

@@ -24,8 +24,8 @@ public class OpenIddictScopeCache<TScope> : IOpenIddictScopeCache<TScope>, IDisp
     private readonly IOpenIddictScopeStore<TScope> _store;
 
     public OpenIddictScopeCache(
-        IOptionsMonitor<OpenIddictCoreOptions> options,
-        IOpenIddictScopeStoreResolver resolver)
+        IOptionsMonitor<OpenIddictCoreOptions> options!!,
+        IOpenIddictScopeStoreResolver resolver!!)
     {
         _cache = new MemoryCache(new MemoryCacheOptions
         {
@@ -37,13 +37,8 @@ public class OpenIddictScopeCache<TScope> : IOpenIddictScopeCache<TScope>, IDisp
     }
 
     /// <inheritdoc/>
-    public async ValueTask AddAsync(TScope scope, CancellationToken cancellationToken)
+    public async ValueTask AddAsync(TScope scope!!, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         _cache.Remove(new
         {
             Method = nameof(FindByIdAsync),
@@ -105,10 +100,10 @@ public class OpenIddictScopeCache<TScope> : IOpenIddictScopeCache<TScope>, IDisp
 
         if (_cache.TryGetValue(parameters, out TScope? scope))
         {
-            return new ValueTask<TScope?>(scope);
+            return new(scope);
         }
 
-        return new ValueTask<TScope?>(ExecuteAsync());
+        return new(ExecuteAsync());
 
         async Task<TScope?> ExecuteAsync()
         {
@@ -139,7 +134,7 @@ public class OpenIddictScopeCache<TScope> : IOpenIddictScopeCache<TScope>, IDisp
 
         if (_cache.TryGetValue(parameters, out TScope? scope))
         {
-            return new ValueTask<TScope?>(scope);
+            return new(scope);
         }
 
         async Task<TScope?> ExecuteAsync()
@@ -154,13 +149,13 @@ public class OpenIddictScopeCache<TScope> : IOpenIddictScopeCache<TScope>, IDisp
             return scope;
         }
 
-        return new ValueTask<TScope?>(ExecuteAsync());
+        return new(ExecuteAsync());
     }
 
     /// <inheritdoc/>
     public IAsyncEnumerable<TScope> FindByNamesAsync(ImmutableArray<string> names, CancellationToken cancellationToken)
     {
-        if (names.Any(name => string.IsNullOrEmpty(name)))
+        if (names.Any(string.IsNullOrEmpty))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0203), nameof(names));
         }
@@ -222,13 +217,8 @@ public class OpenIddictScopeCache<TScope> : IOpenIddictScopeCache<TScope>, IDisp
     }
 
     /// <inheritdoc/>
-    public async ValueTask RemoveAsync(TScope scope, CancellationToken cancellationToken)
+    public async ValueTask RemoveAsync(TScope scope!!, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         var identifier = await _store.GetIdAsync(scope, cancellationToken);
         if (string.IsNullOrEmpty(identifier))
         {
@@ -249,13 +239,8 @@ public class OpenIddictScopeCache<TScope> : IOpenIddictScopeCache<TScope>, IDisp
     /// <param name="scope">The scope to store in the cache entry, if applicable.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns>A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation.</returns>
-    protected virtual async ValueTask CreateEntryAsync(object key, TScope? scope, CancellationToken cancellationToken)
+    protected virtual async ValueTask CreateEntryAsync(object key!!, TScope? scope, CancellationToken cancellationToken)
     {
-        if (key is null)
-        {
-            throw new ArgumentNullException(nameof(key));
-        }
-
         using var entry = _cache.CreateEntry(key);
 
         if (scope is not null)
@@ -281,13 +266,8 @@ public class OpenIddictScopeCache<TScope> : IOpenIddictScopeCache<TScope>, IDisp
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns>A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation.</returns>
     protected virtual async ValueTask CreateEntryAsync(
-        object key, ImmutableArray<TScope> scopes, CancellationToken cancellationToken)
+        object key!!, ImmutableArray<TScope> scopes, CancellationToken cancellationToken)
     {
-        if (key is null)
-        {
-            throw new ArgumentNullException(nameof(key));
-        }
-
         using var entry = _cache.CreateEntry(key);
 
         foreach (var scope in scopes)
@@ -315,13 +295,8 @@ public class OpenIddictScopeCache<TScope> : IOpenIddictScopeCache<TScope>, IDisp
     /// A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation,
     /// whose result returns an expiration signal for the specified scope.
     /// </returns>
-    protected virtual async ValueTask<IChangeToken> CreateExpirationSignalAsync(TScope scope, CancellationToken cancellationToken)
+    protected virtual async ValueTask<IChangeToken> CreateExpirationSignalAsync(TScope scope!!, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         var identifier = await _store.GetIdAsync(scope, cancellationToken);
         if (string.IsNullOrEmpty(identifier))
         {

src/OpenIddict.Core/Caches/OpenIddictTokenCache.cs

@@ -24,8 +24,8 @@ public class OpenIddictTokenCache<TToken> : IOpenIddictTokenCache<TToken>, IDisp
     private readonly IOpenIddictTokenStore<TToken> _store;
 
     public OpenIddictTokenCache(
-        IOptionsMonitor<OpenIddictCoreOptions> options,
-        IOpenIddictTokenStoreResolver resolver)
+        IOptionsMonitor<OpenIddictCoreOptions> options!!,
+        IOpenIddictTokenStoreResolver resolver!!)
     {
         _cache = new MemoryCache(new MemoryCacheOptions
         {
@@ -37,13 +37,8 @@ public class OpenIddictTokenCache<TToken> : IOpenIddictTokenCache<TToken>, IDisp
     }
 
     /// <inheritdoc/>
-    public async ValueTask AddAsync(TToken token, CancellationToken cancellationToken)
+    public async ValueTask AddAsync(TToken token!!, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         _cache.Remove(new
         {
             Method = nameof(FindAsync),
@@ -383,10 +378,10 @@ public class OpenIddictTokenCache<TToken> : IOpenIddictTokenCache<TToken>, IDisp
 
         if (_cache.TryGetValue(parameters, out TToken? token))
         {
-            return new ValueTask<TToken?>(token);
+            return new(token);
         }
 
-        return new ValueTask<TToken?>(ExecuteAsync());
+        return new(ExecuteAsync());
 
         async Task<TToken?> ExecuteAsync()
         {
@@ -417,10 +412,10 @@ public class OpenIddictTokenCache<TToken> : IOpenIddictTokenCache<TToken>, IDisp
 
         if (_cache.TryGetValue(parameters, out TToken? token))
         {
-            return new ValueTask<TToken?>(token);
+            return new(token);
         }
 
-        return new ValueTask<TToken?>(ExecuteAsync());
+        return new(ExecuteAsync());
 
         async Task<TToken?> ExecuteAsync()
         {
@@ -477,13 +472,8 @@ public class OpenIddictTokenCache<TToken> : IOpenIddictTokenCache<TToken>, IDisp
     }
 
     /// <inheritdoc/>
-    public async ValueTask RemoveAsync(TToken token, CancellationToken cancellationToken)
+    public async ValueTask RemoveAsync(TToken token!!, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         var identifier = await _store.GetIdAsync(token, cancellationToken);
         if (string.IsNullOrEmpty(identifier))
         {
@@ -504,13 +494,8 @@ public class OpenIddictTokenCache<TToken> : IOpenIddictTokenCache<TToken>, IDisp
     /// <param name="token">The token to store in the cache entry, if applicable.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns>A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation.</returns>
-    protected virtual async ValueTask CreateEntryAsync(object key, TToken? token, CancellationToken cancellationToken)
+    protected virtual async ValueTask CreateEntryAsync(object key!!, TToken? token, CancellationToken cancellationToken)
     {
-        if (key is null)
-        {
-            throw new ArgumentNullException(nameof(key));
-        }
-
         using var entry = _cache.CreateEntry(key);
 
         if (token is not null)
@@ -536,13 +521,8 @@ public class OpenIddictTokenCache<TToken> : IOpenIddictTokenCache<TToken>, IDisp
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns>A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation.</returns>
     protected virtual async ValueTask CreateEntryAsync(
-        object key, ImmutableArray<TToken> tokens, CancellationToken cancellationToken)
+        object key!!, ImmutableArray<TToken> tokens, CancellationToken cancellationToken)
     {
-        if (key is null)
-        {
-            throw new ArgumentNullException(nameof(key));
-        }
-
         using var entry = _cache.CreateEntry(key);
 
         foreach (var token in tokens)
@@ -570,13 +550,8 @@ public class OpenIddictTokenCache<TToken> : IOpenIddictTokenCache<TToken>, IDisp
     /// A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation,
     /// whose result returns an expiration signal for the specified token.
     /// </returns>
-    protected virtual async ValueTask<IChangeToken> CreateExpirationSignalAsync(TToken token, CancellationToken cancellationToken)
+    protected virtual async ValueTask<IChangeToken> CreateExpirationSignalAsync(TToken token!!, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         var identifier = await _store.GetIdAsync(token, cancellationToken);
         if (string.IsNullOrEmpty(identifier))
         {

src/OpenIddict.Core/Managers/OpenIddictApplicationManager.cs

@@ -41,10 +41,10 @@ namespace OpenIddict.Core;
 public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplicationManager where TApplication : class
 {
     public OpenIddictApplicationManager(
-        IOpenIddictApplicationCache<TApplication> cache,
-        ILogger<OpenIddictApplicationManager<TApplication>> logger,
-        IOptionsMonitor<OpenIddictCoreOptions> options,
-        IOpenIddictApplicationStoreResolver resolver)
+        IOpenIddictApplicationCache<TApplication> cache!!,
+        ILogger<OpenIddictApplicationManager<TApplication>> logger!!,
+        IOptionsMonitor<OpenIddictCoreOptions> options!!,
+        IOpenIddictApplicationStoreResolver resolver!!)
     {
         Cache = cache;
         Logger = logger;
@@ -94,15 +94,8 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// whose result returns the number of applications that match the specified query.
     /// </returns>
     public virtual ValueTask<long> CountAsync<TResult>(
-        Func<IQueryable<TApplication>, IQueryable<TResult>> query, CancellationToken cancellationToken = default)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return Store.CountAsync(query, cancellationToken);
-    }
+        Func<IQueryable<TApplication>, IQueryable<TResult>> query!!, CancellationToken cancellationToken = default)
+        => Store.CountAsync(query, cancellationToken);
 
     /// <summary>
     /// Creates a new application.
@@ -126,13 +119,8 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// <returns>
     /// A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation.
     /// </returns>
-    public virtual async ValueTask CreateAsync(TApplication application, string? secret, CancellationToken cancellationToken = default)
+    public virtual async ValueTask CreateAsync(TApplication application!!, string? secret, CancellationToken cancellationToken = default)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         if (!string.IsNullOrEmpty(await Store.GetClientSecretAsync(application, cancellationToken)))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0206), nameof(application));
@@ -201,13 +189,8 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// whose result returns the unique identifier associated with the application.
     /// </returns>
     public virtual async ValueTask<TApplication> CreateAsync(
-        OpenIddictApplicationDescriptor descriptor, CancellationToken cancellationToken = default)
+        OpenIddictApplicationDescriptor descriptor!!, CancellationToken cancellationToken = default)
     {
-        if (descriptor is null)
-        {
-            throw new ArgumentNullException(nameof(descriptor));
-        }
-
         var application = await Store.InstantiateAsync(cancellationToken);
         if (application is null)
         {
@@ -238,13 +221,8 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// <returns>
     /// A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation.
     /// </returns>
-    public virtual async ValueTask DeleteAsync(TApplication application, CancellationToken cancellationToken = default)
+    public virtual async ValueTask DeleteAsync(TApplication application!!, CancellationToken cancellationToken = default)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         if (!Options.CurrentValue.DisableEntityCaching)
         {
             await Cache.RemoveAsync(application, cancellationToken);
@@ -423,15 +401,8 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// whose result returns the first element returned when executing the query.
     /// </returns>
     public virtual ValueTask<TResult?> GetAsync<TResult>(
-        Func<IQueryable<TApplication>, IQueryable<TResult>> query, CancellationToken cancellationToken = default)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return GetAsync(static (applications, query) => query(applications), query, cancellationToken);
-    }
+        Func<IQueryable<TApplication>, IQueryable<TResult>> query!!, CancellationToken cancellationToken = default)
+        => GetAsync(static (applications, query) => query(applications), query, cancellationToken);
 
     /// <summary>
     /// Executes the specified query and returns the first element.
@@ -446,16 +417,9 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// whose result returns the first element returned when executing the query.
     /// </returns>
     public virtual ValueTask<TResult?> GetAsync<TState, TResult>(
-        Func<IQueryable<TApplication>, TState, IQueryable<TResult>> query,
+        Func<IQueryable<TApplication>, TState, IQueryable<TResult>> query!!,
         TState state, CancellationToken cancellationToken = default)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return Store.GetAsync(query, state, cancellationToken);
-    }
+        => Store.GetAsync(query, state, cancellationToken);
 
     /// <summary>
     /// Retrieves the client identifier associated with an application.
@@ -467,15 +431,8 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// whose result returns the client identifier associated with the application.
     /// </returns>
     public virtual ValueTask<string?> GetClientIdAsync(
-        TApplication application, CancellationToken cancellationToken = default)
-    {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        return Store.GetClientIdAsync(application, cancellationToken);
-    }
+        TApplication application!!, CancellationToken cancellationToken = default)
+        => Store.GetClientIdAsync(application, cancellationToken);
 
     /// <summary>
     /// Retrieves the client type associated with an application.
@@ -487,15 +444,8 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// whose result returns the client type of the application (by default, "public").
     /// </returns>
     public virtual ValueTask<string?> GetClientTypeAsync(
-        TApplication application, CancellationToken cancellationToken = default)
-    {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        return Store.GetClientTypeAsync(application, cancellationToken);
-    }
+        TApplication application!!, CancellationToken cancellationToken = default)
+        => Store.GetClientTypeAsync(application, cancellationToken);
 
     /// <summary>
     /// Retrieves the consent type associated with an application.
@@ -507,13 +457,8 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// whose result returns the consent type of the application (by default, "explicit").
     /// </returns>
     public virtual async ValueTask<string?> GetConsentTypeAsync(
-        TApplication application, CancellationToken cancellationToken = default)
+        TApplication application!!, CancellationToken cancellationToken = default)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         var type = await Store.GetConsentTypeAsync(application, cancellationToken);
         if (string.IsNullOrEmpty(type))
         {
@@ -533,15 +478,8 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// whose result returns the display name associated with the application.
     /// </returns>
     public virtual ValueTask<string?> GetDisplayNameAsync(
-        TApplication application, CancellationToken cancellationToken = default)
-    {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        return Store.GetDisplayNameAsync(application, cancellationToken);
-    }
+        TApplication application!!, CancellationToken cancellationToken = default)
+        => Store.GetDisplayNameAsync(application, cancellationToken);
 
     /// <summary>
     /// Retrieves the localized display names associated with an application.
@@ -553,21 +491,9 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// whose result returns all the localized display names associated with the application.
     /// </returns>
     public virtual async ValueTask<ImmutableDictionary<CultureInfo, string>> GetDisplayNamesAsync(
-        TApplication application, CancellationToken cancellationToken = default)
-    {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        var names = await Store.GetDisplayNamesAsync(application, cancellationToken);
-        if (names is null || names.Count == 0)
-        {
-            return ImmutableDictionary.Create<CultureInfo, string>();
-        }
-
-        return names;
-    }
+        TApplication application!!, CancellationToken cancellationToken = default)
+        => await Store.GetDisplayNamesAsync(application, cancellationToken) is { Count: > 0 } names ?
+            names : ImmutableDictionary.Create<CultureInfo, string>();
 
     /// <summary>
     /// Retrieves the unique identifier associated with an application.
@@ -578,15 +504,8 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// A <see cref="ValueTask{TResult}"/> that can be used to monitor the asynchronous operation,
     /// whose result returns the unique identifier associated with the application.
     /// </returns>
-    public virtual ValueTask<string?> GetIdAsync(TApplication application, CancellationToken cancellationToken = default)
-    {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        return Store.GetIdAsync(application, cancellationToken);
-    }
+    public virtual ValueTask<string?> GetIdAsync(TApplication application!!, CancellationToken cancellationToken = default)
+        => Store.GetIdAsync(application, cancellationToken);
 
     /// <summary>
     /// Retrieves the localized display name associated with an application
@@ -616,20 +535,10 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// whose result returns the matching localized display name associated with the application.
     /// </returns>
     public virtual async ValueTask<string?> GetLocalizedDisplayNameAsync(
-        TApplication application, CultureInfo culture, CancellationToken cancellationToken = default)
+        TApplication application!!, CultureInfo culture!!, CancellationToken cancellationToken = default)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        if (culture is null)
-        {
-            throw new ArgumentNullException(nameof(culture));
-        }
-
         var names = await Store.GetDisplayNamesAsync(application, cancellationToken);
-        if (names is null || names.IsEmpty)
+        if (names is not { IsEmpty: false })
         {
             return await Store.GetDisplayNameAsync(application, cancellationToken);
         }
@@ -659,15 +568,8 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// whose result returns all the permissions associated with the application.
     /// </returns>
     public virtual ValueTask<ImmutableArray<string>> GetPermissionsAsync(
-        TApplication application, CancellationToken cancellationToken = default)
-    {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        return Store.GetPermissionsAsync(application, cancellationToken);
-    }
+        TApplication application!!, CancellationToken cancellationToken = default)
+        => Store.GetPermissionsAsync(application, cancellationToken);
 
     /// <summary>
     /// Retrieves the logout callback addresses associated with an application.
@@ -679,15 +581,8 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// whose result returns all the post_logout_redirect_uri associated with the application.
     /// </returns>
     public virtual ValueTask<ImmutableArray<string>> GetPostLogoutRedirectUrisAsync(
-        TApplication application, CancellationToken cancellationToken = default)
-    {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        return Store.GetPostLogoutRedirectUrisAsync(application, cancellationToken);
-    }
+        TApplication application!!, CancellationToken cancellationToken = default)
+        => Store.GetPostLogoutRedirectUrisAsync(application, cancellationToken);
 
     /// <summary>
     /// Retrieves the additional properties associated with an application.
@@ -699,15 +594,8 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// whose result returns all the additional properties associated with the application.
     /// </returns>
     public virtual ValueTask<ImmutableDictionary<string, JsonElement>> GetPropertiesAsync(
-        TApplication application, CancellationToken cancellationToken = default)
-    {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        return Store.GetPropertiesAsync(application, cancellationToken);
-    }
+        TApplication application!!, CancellationToken cancellationToken = default)
+        => Store.GetPropertiesAsync(application, cancellationToken);
 
     /// <summary>
     /// Retrieves the callback addresses associated with an application.
@@ -719,15 +607,8 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// whose result returns all the redirect_uri associated with the application.
     /// </returns>
     public virtual ValueTask<ImmutableArray<string>> GetRedirectUrisAsync(
-        TApplication application, CancellationToken cancellationToken = default)
-    {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        return Store.GetRedirectUrisAsync(application, cancellationToken);
-    }
+        TApplication application!!, CancellationToken cancellationToken = default)
+        => Store.GetRedirectUrisAsync(application, cancellationToken);
 
     /// <summary>
     /// Retrieves the requirements associated with an application.
@@ -739,15 +620,8 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// whose result returns all the requirements associated with the application.
     /// </returns>
     public virtual ValueTask<ImmutableArray<string>> GetRequirementsAsync(
-        TApplication application, CancellationToken cancellationToken = default)
-    {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        return Store.GetRequirementsAsync(application, cancellationToken);
-    }
+        TApplication application!!, CancellationToken cancellationToken = default)
+        => Store.GetRequirementsAsync(application, cancellationToken);
 
     /// <summary>
     /// Determines whether a given application has the specified client type.
@@ -757,13 +631,8 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns><c>true</c> if the application has the specified client type, <c>false</c> otherwise.</returns>
     public virtual async ValueTask<bool> HasClientTypeAsync(
-        TApplication application, string type, CancellationToken cancellationToken = default)
+        TApplication application!!, string type, CancellationToken cancellationToken = default)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         if (string.IsNullOrEmpty(type))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0209), nameof(type));
@@ -780,13 +649,8 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns><c>true</c> if the application has the specified consent type, <c>false</c> otherwise.</returns>
     public virtual async ValueTask<bool> HasConsentTypeAsync(
-        TApplication application, string type, CancellationToken cancellationToken = default)
+        TApplication application!!, string type, CancellationToken cancellationToken = default)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         if (string.IsNullOrEmpty(type))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0210), nameof(type));
@@ -803,13 +667,8 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns><c>true</c> if the application has been granted the specified permission, <c>false</c> otherwise.</returns>
     public virtual async ValueTask<bool> HasPermissionAsync(
-        TApplication application, string permission, CancellationToken cancellationToken = default)
+        TApplication application!!, string permission, CancellationToken cancellationToken = default)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         if (string.IsNullOrEmpty(permission))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0211), nameof(permission));
@@ -826,13 +685,8 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns><c>true</c> if the requirement has been enforced for the specified application, <c>false</c> otherwise.</returns>
     public virtual async ValueTask<bool> HasRequirementAsync(
-        TApplication application, string requirement, CancellationToken cancellationToken = default)
+        TApplication application!!, string requirement, CancellationToken cancellationToken = default)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         if (string.IsNullOrEmpty(requirement))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0212), nameof(requirement));
@@ -860,15 +714,8 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns>All the elements returned when executing the specified query.</returns>
     public virtual IAsyncEnumerable<TResult> ListAsync<TResult>(
-        Func<IQueryable<TApplication>, IQueryable<TResult>> query, CancellationToken cancellationToken = default)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return ListAsync(static (applications, query) => query(applications), query, cancellationToken);
-    }
+        Func<IQueryable<TApplication>, IQueryable<TResult>> query!!, CancellationToken cancellationToken = default)
+        => ListAsync(static (applications, query) => query(applications), query, cancellationToken);
 
     /// <summary>
     /// Executes the specified query and returns all the corresponding elements.
@@ -880,16 +727,9 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns>All the elements returned when executing the specified query.</returns>
     public virtual IAsyncEnumerable<TResult> ListAsync<TState, TResult>(
-        Func<IQueryable<TApplication>, TState, IQueryable<TResult>> query,
+        Func<IQueryable<TApplication>, TState, IQueryable<TResult>> query!!,
         TState state, CancellationToken cancellationToken = default)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return Store.ListAsync(query, state, cancellationToken);
-    }
+        => Store.ListAsync(query, state, cancellationToken);
 
     /// <summary>
     /// Populates the application using the specified descriptor.
@@ -900,19 +740,9 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// <returns>
     /// A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation.
     /// </returns>
-    public virtual async ValueTask PopulateAsync(TApplication application,
-        OpenIddictApplicationDescriptor descriptor, CancellationToken cancellationToken = default)
+    public virtual async ValueTask PopulateAsync(TApplication application!!,
+        OpenIddictApplicationDescriptor descriptor!!, CancellationToken cancellationToken = default)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        if (descriptor is null)
-        {
-            throw new ArgumentNullException(nameof(descriptor));
-        }
-
         await Store.SetClientIdAsync(application, descriptor.ClientId, cancellationToken);
         await Store.SetClientSecretAsync(application, descriptor.ClientSecret, cancellationToken);
         await Store.SetClientTypeAsync(application, descriptor.Type, cancellationToken);
@@ -938,19 +768,9 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation.
     /// </returns>
     public virtual async ValueTask PopulateAsync(
-        OpenIddictApplicationDescriptor descriptor,
-        TApplication application, CancellationToken cancellationToken = default)
+        OpenIddictApplicationDescriptor descriptor!!,
+        TApplication application!!, CancellationToken cancellationToken = default)
     {
-        if (descriptor is null)
-        {
-            throw new ArgumentNullException(nameof(descriptor));
-        }
-
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         descriptor.ClientId = await Store.GetClientIdAsync(application, cancellationToken);
         descriptor.ClientSecret = await Store.GetClientSecretAsync(application, cancellationToken);
         descriptor.ConsentType = await Store.GetConsentTypeAsync(application, cancellationToken);
@@ -1018,13 +838,8 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// <returns>
     /// A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation.
     /// </returns>
-    public virtual async ValueTask UpdateAsync(TApplication application, CancellationToken cancellationToken = default)
+    public virtual async ValueTask UpdateAsync(TApplication application!!, CancellationToken cancellationToken = default)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         var results = await GetValidationResultsAsync(application, cancellationToken);
         if (results.Any(result => result != ValidationResult.Success))
         {
@@ -1073,13 +888,8 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// <returns>
     /// A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation.
     /// </returns>
-    public virtual async ValueTask UpdateAsync(TApplication application, string? secret, CancellationToken cancellationToken = default)
+    public virtual async ValueTask UpdateAsync(TApplication application!!, string? secret, CancellationToken cancellationToken = default)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         if (string.IsNullOrEmpty(secret))
         {
             await Store.SetClientSecretAsync(application, null, cancellationToken);
@@ -1103,18 +913,9 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// <returns>
     /// A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation.
     /// </returns>
-    public virtual async ValueTask UpdateAsync(TApplication application,
-        OpenIddictApplicationDescriptor descriptor, CancellationToken cancellationToken = default)
+    public virtual async ValueTask UpdateAsync(TApplication application!!,
+        OpenIddictApplicationDescriptor descriptor!!, CancellationToken cancellationToken = default)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        if (descriptor is null)
-        {
-            throw new ArgumentNullException(nameof(descriptor));
-        }
 
         // Store the original client secret for later comparison.
         var comparand = await Store.GetClientSecretAsync(application, cancellationToken);
@@ -1139,12 +940,8 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns>The validation error encountered when validating the application.</returns>
     public virtual async IAsyncEnumerable<ValidationResult> ValidateAsync(
-        TApplication application, [EnumeratorCancellation] CancellationToken cancellationToken = default)
+        TApplication application!!, [EnumeratorCancellation] CancellationToken cancellationToken = default)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
 
         // Ensure the client_id is not null or empty and is not already used for a different application.
         var identifier = await Store.GetClientIdAsync(application, cancellationToken);
@@ -1254,12 +1051,8 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// whose result returns a boolean indicating whether the client secret was valid.
     /// </returns>
     public virtual async ValueTask<bool> ValidateClientSecretAsync(
-        TApplication application, string secret, CancellationToken cancellationToken = default)
+        TApplication application!!, string secret, CancellationToken cancellationToken = default)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
         if (string.IsNullOrEmpty(secret))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0216), nameof(secret));
@@ -1301,13 +1094,8 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// whose result returns a boolean indicating whether the redirect_uri was valid.
     /// </returns>
     public virtual async ValueTask<bool> ValidateRedirectUriAsync(
-        TApplication application, string address, CancellationToken cancellationToken = default)
+        TApplication application!!, string address, CancellationToken cancellationToken = default)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         if (string.IsNullOrEmpty(address))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0143), nameof(address));
@@ -1358,7 +1146,7 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
 
         var hash = HashSecret(secret, salt, HashAlgorithmName.SHA256, iterations: 10_000, length: 256 / 8);
 
-        return new ValueTask<string>(
+        return new(
 #if SUPPORTS_BASE64_SPAN_CONVERSION
             Convert.ToBase64String(hash)
 #else
@@ -1431,14 +1219,14 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
 
         try
         {
-            return new ValueTask<bool>(VerifyHashedSecret(comparand, secret));
+            return new(VerifyHashedSecret(comparand, secret));
         }
 
         catch (Exception exception)
         {
             Logger.LogWarning(exception, SR.GetResourceString(SR.ID6163));
 
-            return new ValueTask<bool>(false);
+            return new(false);
         }
 
         // Note: the following logic deliberately uses the same format as CryptoHelper (used in OpenIddict 1.x/2.x),

src/OpenIddict.Core/Managers/OpenIddictAuthorizationManager.cs

@@ -28,10 +28,10 @@ namespace OpenIddict.Core;
 public class OpenIddictAuthorizationManager<TAuthorization> : IOpenIddictAuthorizationManager where TAuthorization : class
 {
     public OpenIddictAuthorizationManager(
-        IOpenIddictAuthorizationCache<TAuthorization> cache,
-        ILogger<OpenIddictAuthorizationManager<TAuthorization>> logger,
-        IOptionsMonitor<OpenIddictCoreOptions> options,
-        IOpenIddictAuthorizationStoreResolver resolver)
+        IOpenIddictAuthorizationCache<TAuthorization> cache!!,
+        ILogger<OpenIddictAuthorizationManager<TAuthorization>> logger!!,
+        IOptionsMonitor<OpenIddictCoreOptions> options!!,
+        IOpenIddictAuthorizationStoreResolver resolver!!)
     {
         Cache = cache;
         Logger = logger;
@@ -81,15 +81,8 @@ public class OpenIddictAuthorizationManager<TAuthorization> : IOpenIddictAuthori
     /// whose result returns the number of authorizations that match the specified query.
     /// </returns>
     public virtual ValueTask<long> CountAsync<TResult>(
-        Func<IQueryable<TAuthorization>, IQueryable<TResult>> query, CancellationToken cancellationToken = default)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return Store.CountAsync(query, cancellationToken);
-    }
+        Func<IQueryable<TAuthorization>, IQueryable<TResult>> query!!, CancellationToken cancellationToken = default)
+        => Store.CountAsync(query, cancellationToken);
 
     /// <summary>
     /// Creates a new authorization.
@@ -99,13 +92,8 @@ public class OpenIddictAuthorizationManager<TAuthorization> : IOpenIddictAuthori
     /// <returns>
     /// A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation.
     /// </returns>
-    public virtual async ValueTask CreateAsync(TAuthorization authorization, CancellationToken cancellationToken = default)
+    public virtual async ValueTask CreateAsync(TAuthorization authorization!!, CancellationToken cancellationToken = default)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         // If no status was explicitly specified, assume that the authorization is valid.
         if (string.IsNullOrEmpty(await Store.GetStatusAsync(authorization, cancellationToken)))
         {
@@ -157,13 +145,8 @@ public class OpenIddictAuthorizationManager<TAuthorization> : IOpenIddictAuthori
     /// A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation, whose result returns the authorization.
     /// </returns>
     public virtual async ValueTask<TAuthorization> CreateAsync(
-        OpenIddictAuthorizationDescriptor descriptor, CancellationToken cancellationToken = default)
+        OpenIddictAuthorizationDescriptor descriptor!!, CancellationToken cancellationToken = default)
     {
-        if (descriptor is null)
-        {
-            throw new ArgumentNullException(nameof(descriptor));
-        }
-
         var authorization = await Store.InstantiateAsync(cancellationToken);
         if (authorization is null)
         {
@@ -189,14 +172,9 @@ public class OpenIddictAuthorizationManager<TAuthorization> : IOpenIddictAuthori
     /// A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation, whose result returns the authorization.
     /// </returns>
     public virtual ValueTask<TAuthorization> CreateAsync(
-        ClaimsPrincipal principal, string subject, string client,
+        ClaimsPrincipal principal!!, string subject, string client,
         string type, ImmutableArray<string> scopes, CancellationToken cancellationToken = default)
     {
-        if (principal is null)
-        {
-            throw new ArgumentNullException(nameof(principal));
-        }
-
         if (string.IsNullOrEmpty(subject))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0198), nameof(subject));
@@ -235,13 +213,8 @@ public class OpenIddictAuthorizationManager<TAuthorization> : IOpenIddictAuthori
     /// <returns>
     /// A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation.
     /// </returns>
-    public virtual async ValueTask DeleteAsync(TAuthorization authorization, CancellationToken cancellationToken = default)
+    public virtual async ValueTask DeleteAsync(TAuthorization authorization!!, CancellationToken cancellationToken = default)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         if (!Options.CurrentValue.DisableEntityCaching)
         {
             await Cache.RemoveAsync(authorization, cancellationToken);
@@ -614,15 +587,8 @@ public class OpenIddictAuthorizationManager<TAuthorization> : IOpenIddictAuthori
     /// whose result returns the application identifier associated with the authorization.
     /// </returns>
     public virtual ValueTask<string?> GetApplicationIdAsync(
-        TAuthorization authorization, CancellationToken cancellationToken = default)
-    {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
-        return Store.GetApplicationIdAsync(authorization, cancellationToken);
-    }
+        TAuthorization authorization!!, CancellationToken cancellationToken = default)
+        => Store.GetApplicationIdAsync(authorization, cancellationToken);
 
     /// <summary>
     /// Executes the specified query and returns the first element.
@@ -635,15 +601,8 @@ public class OpenIddictAuthorizationManager<TAuthorization> : IOpenIddictAuthori
     /// whose result returns the first element returned when executing the query.
     /// </returns>
     public virtual ValueTask<TResult?> GetAsync<TResult>(
-        Func<IQueryable<TAuthorization>, IQueryable<TResult>> query, CancellationToken cancellationToken = default)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return GetAsync(static (authorizations, query) => query(authorizations), query, cancellationToken);
-    }
+        Func<IQueryable<TAuthorization>, IQueryable<TResult>> query!!, CancellationToken cancellationToken = default)
+        => GetAsync(static (authorizations, query) => query(authorizations), query, cancellationToken);
 
     /// <summary>
     /// Executes the specified query and returns the first element.
@@ -658,16 +617,9 @@ public class OpenIddictAuthorizationManager<TAuthorization> : IOpenIddictAuthori
     /// whose result returns the first element returned when executing the query.
     /// </returns>
     public virtual ValueTask<TResult?> GetAsync<TState, TResult>(
-        Func<IQueryable<TAuthorization>, TState, IQueryable<TResult>> query,
+        Func<IQueryable<TAuthorization>, TState, IQueryable<TResult>> query!!,
         TState state, CancellationToken cancellationToken = default)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return Store.GetAsync(query, state, cancellationToken);
-    }
+        => Store.GetAsync(query, state, cancellationToken);
 
     /// <summary>
     /// Retrieves the creation date associated with an authorization.
@@ -679,15 +631,8 @@ public class OpenIddictAuthorizationManager<TAuthorization> : IOpenIddictAuthori
     /// whose result returns the creation date associated with the specified authorization.
     /// </returns>
     public virtual ValueTask<DateTimeOffset?> GetCreationDateAsync(
-        TAuthorization authorization, CancellationToken cancellationToken = default)
-    {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
-        return Store.GetCreationDateAsync(authorization, cancellationToken);
-    }
+        TAuthorization authorization!!, CancellationToken cancellationToken = default)
+        => Store.GetCreationDateAsync(authorization, cancellationToken);
 
     /// <summary>
     /// Retrieves the unique identifier associated with an authorization.
@@ -698,15 +643,8 @@ public class OpenIddictAuthorizationManager<TAuthorization> : IOpenIddictAuthori
     /// A <see cref="ValueTask{TResult}"/> that can be used to monitor the asynchronous operation,
     /// whose result returns the unique identifier associated with the authorization.
     /// </returns>
-    public virtual ValueTask<string?> GetIdAsync(TAuthorization authorization, CancellationToken cancellationToken = default)
-    {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
-        return Store.GetIdAsync(authorization, cancellationToken);
-    }
+    public virtual ValueTask<string?> GetIdAsync(TAuthorization authorization!!, CancellationToken cancellationToken = default)
+        => Store.GetIdAsync(authorization, cancellationToken);
 
     /// <summary>
     /// Retrieves the additional properties associated with an authorization.
@@ -718,15 +656,8 @@ public class OpenIddictAuthorizationManager<TAuthorization> : IOpenIddictAuthori
     /// whose result returns all the additional properties associated with the authorization.
     /// </returns>
     public virtual ValueTask<ImmutableDictionary<string, JsonElement>> GetPropertiesAsync(
-        TAuthorization authorization, CancellationToken cancellationToken = default)
-    {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
-        return Store.GetPropertiesAsync(authorization, cancellationToken);
-    }
+        TAuthorization authorization!!, CancellationToken cancellationToken = default)
+        => Store.GetPropertiesAsync(authorization, cancellationToken);
 
     /// <summary>
     /// Retrieves the scopes associated with an authorization.
@@ -738,15 +669,8 @@ public class OpenIddictAuthorizationManager<TAuthorization> : IOpenIddictAuthori
     /// whose result returns the scopes associated with the specified authorization.
     /// </returns>
     public virtual ValueTask<ImmutableArray<string>> GetScopesAsync(
-        TAuthorization authorization, CancellationToken cancellationToken = default)
-    {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
-        return Store.GetScopesAsync(authorization, cancellationToken);
-    }
+        TAuthorization authorization!!, CancellationToken cancellationToken = default)
+        => Store.GetScopesAsync(authorization, cancellationToken);
 
     /// <summary>
     /// Retrieves the status associated with an authorization.
@@ -758,15 +682,8 @@ public class OpenIddictAuthorizationManager<TAuthorization> : IOpenIddictAuthori
     /// whose result returns the status associated with the specified authorization.
     /// </returns>
     public virtual ValueTask<string?> GetStatusAsync(
-        TAuthorization authorization, CancellationToken cancellationToken = default)
-    {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
-        return Store.GetStatusAsync(authorization, cancellationToken);
-    }
+        TAuthorization authorization!!, CancellationToken cancellationToken = default)
+        => Store.GetStatusAsync(authorization, cancellationToken);
 
     /// <summary>
     /// Retrieves the subject associated with an authorization.
@@ -778,15 +695,8 @@ public class OpenIddictAuthorizationManager<TAuthorization> : IOpenIddictAuthori
     /// whose result returns the subject associated with the specified authorization.
     /// </returns>
     public virtual ValueTask<string?> GetSubjectAsync(
-        TAuthorization authorization, CancellationToken cancellationToken = default)
-    {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
-        return Store.GetSubjectAsync(authorization, cancellationToken);
-    }
+        TAuthorization authorization!!, CancellationToken cancellationToken = default)
+        => Store.GetSubjectAsync(authorization, cancellationToken);
 
     /// <summary>
     /// Retrieves the type associated with an authorization.
@@ -798,15 +708,8 @@ public class OpenIddictAuthorizationManager<TAuthorization> : IOpenIddictAuthori
     /// whose result returns the type associated with the specified authorization.
     /// </returns>
     public virtual ValueTask<string?> GetTypeAsync(
-        TAuthorization authorization, CancellationToken cancellationToken = default)
-    {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
-        return Store.GetTypeAsync(authorization, cancellationToken);
-    }
+        TAuthorization authorization!!, CancellationToken cancellationToken = default)
+        => Store.GetTypeAsync(authorization, cancellationToken);
 
     /// <summary>
     /// Determines whether the specified scopes are included in the authorization.
@@ -815,17 +718,10 @@ public class OpenIddictAuthorizationManager<TAuthorization> : IOpenIddictAuthori
     /// <param name="scopes">The scopes.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns><c>true</c> if the scopes are included in the authorization, <c>false</c> otherwise.</returns>
-    public virtual async ValueTask<bool> HasScopesAsync(TAuthorization authorization,
+    public virtual async ValueTask<bool> HasScopesAsync(TAuthorization authorization!!,
         ImmutableArray<string> scopes, CancellationToken cancellationToken = default)
-    {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
-        return new HashSet<string>(await Store.GetScopesAsync(
+        => new HashSet<string>(await Store.GetScopesAsync(
             authorization, cancellationToken), StringComparer.Ordinal).IsSupersetOf(scopes);
-    }
 
     /// <summary>
     /// Determines whether a given authorization has the specified status.
@@ -834,14 +730,9 @@ public class OpenIddictAuthorizationManager<TAuthorization> : IOpenIddictAuthori
     /// <param name="status">The expected status.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns><c>true</c> if the authorization has the specified status, <c>false</c> otherwise.</returns>
-    public virtual async ValueTask<bool> HasStatusAsync(TAuthorization authorization,
+    public virtual async ValueTask<bool> HasStatusAsync(TAuthorization authorization!!,
         string status, CancellationToken cancellationToken = default)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         if (string.IsNullOrEmpty(status))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0199), nameof(status));
@@ -858,13 +749,8 @@ public class OpenIddictAuthorizationManager<TAuthorization> : IOpenIddictAuthori
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns><c>true</c> if the authorization has the specified type, <c>false</c> otherwise.</returns>
     public virtual async ValueTask<bool> HasTypeAsync(
-        TAuthorization authorization, string type, CancellationToken cancellationToken = default)
+        TAuthorization authorization!!, string type, CancellationToken cancellationToken = default)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         if (string.IsNullOrEmpty(type))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0200), nameof(type));
@@ -892,15 +778,8 @@ public class OpenIddictAuthorizationManager<TAuthorization> : IOpenIddictAuthori
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns>All the elements returned when executing the specified query.</returns>
     public virtual IAsyncEnumerable<TResult> ListAsync<TResult>(
-        Func<IQueryable<TAuthorization>, IQueryable<TResult>> query, CancellationToken cancellationToken = default)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return ListAsync(static (authorizations, query) => query(authorizations), query, cancellationToken);
-    }
+        Func<IQueryable<TAuthorization>, IQueryable<TResult>> query!!, CancellationToken cancellationToken = default)
+        => ListAsync(static (authorizations, query) => query(authorizations), query, cancellationToken);
 
     /// <summary>
     /// Executes the specified query and returns all the corresponding elements.
@@ -912,16 +791,9 @@ public class OpenIddictAuthorizationManager<TAuthorization> : IOpenIddictAuthori
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns>All the elements returned when executing the specified query.</returns>
     public virtual IAsyncEnumerable<TResult> ListAsync<TState, TResult>(
-        Func<IQueryable<TAuthorization>, TState, IQueryable<TResult>> query,
+        Func<IQueryable<TAuthorization>, TState, IQueryable<TResult>> query!!,
         TState state, CancellationToken cancellationToken = default)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return Store.ListAsync(query, state, cancellationToken);
-    }
+        => Store.ListAsync(query, state, cancellationToken);
 
     /// <summary>
     /// Populates the authorization using the specified descriptor.
@@ -932,19 +804,9 @@ public class OpenIddictAuthorizationManager<TAuthorization> : IOpenIddictAuthori
     /// <returns>
     /// A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation.
     /// </returns>
-    public virtual async ValueTask PopulateAsync(TAuthorization authorization,
-        OpenIddictAuthorizationDescriptor descriptor, CancellationToken cancellationToken = default)
+    public virtual async ValueTask PopulateAsync(TAuthorization authorization!!,
+        OpenIddictAuthorizationDescriptor descriptor!!, CancellationToken cancellationToken = default)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
-        if (descriptor is null)
-        {
-            throw new ArgumentNullException(nameof(descriptor));
-        }
-
         await Store.SetApplicationIdAsync(authorization, descriptor.ApplicationId, cancellationToken);
         await Store.SetCreationDateAsync(authorization, descriptor.CreationDate, cancellationToken);
         await Store.SetPropertiesAsync(authorization, descriptor.Properties.ToImmutableDictionary(), cancellationToken);
@@ -964,19 +826,9 @@ public class OpenIddictAuthorizationManager<TAuthorization> : IOpenIddictAuthori
     /// A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation.
     /// </returns>
     public virtual async ValueTask PopulateAsync(
-        OpenIddictAuthorizationDescriptor descriptor,
-        TAuthorization authorization, CancellationToken cancellationToken = default)
+        OpenIddictAuthorizationDescriptor descriptor!!,
+        TAuthorization authorization!!, CancellationToken cancellationToken = default)
     {
-        if (descriptor is null)
-        {
-            throw new ArgumentNullException(nameof(descriptor));
-        }
-
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         descriptor.ApplicationId = await Store.GetApplicationIdAsync(authorization, cancellationToken);
         descriptor.CreationDate = await Store.GetCreationDateAsync(authorization, cancellationToken);
         descriptor.Scopes.Clear();
@@ -1014,13 +866,8 @@ public class OpenIddictAuthorizationManager<TAuthorization> : IOpenIddictAuthori
     /// <param name="authorization">The authorization to revoke.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns><c>true</c> if the authorization was successfully revoked, <c>false</c> otherwise.</returns>
-    public virtual async ValueTask<bool> TryRevokeAsync(TAuthorization authorization, CancellationToken cancellationToken = default)
+    public virtual async ValueTask<bool> TryRevokeAsync(TAuthorization authorization!!, CancellationToken cancellationToken = default)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         var status = await Store.GetStatusAsync(authorization, cancellationToken);
         if (string.Equals(status, Statuses.Revoked, StringComparison.OrdinalIgnoreCase))
         {
@@ -1061,13 +908,8 @@ public class OpenIddictAuthorizationManager<TAuthorization> : IOpenIddictAuthori
     /// <returns>
     /// A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation.
     /// </returns>
-    public virtual async ValueTask UpdateAsync(TAuthorization authorization, CancellationToken cancellationToken = default)
+    public virtual async ValueTask UpdateAsync(TAuthorization authorization!!, CancellationToken cancellationToken = default)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         var results = await GetValidationResultsAsync(authorization, cancellationToken);
         if (results.Any(result => result != ValidationResult.Success))
         {
@@ -1114,19 +956,9 @@ public class OpenIddictAuthorizationManager<TAuthorization> : IOpenIddictAuthori
     /// <returns>
     /// A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation.
     /// </returns>
-    public virtual async ValueTask UpdateAsync(TAuthorization authorization,
-        OpenIddictAuthorizationDescriptor descriptor, CancellationToken cancellationToken = default)
+    public virtual async ValueTask UpdateAsync(TAuthorization authorization!!,
+        OpenIddictAuthorizationDescriptor descriptor!!, CancellationToken cancellationToken = default)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
-        if (descriptor is null)
-        {
-            throw new ArgumentNullException(nameof(descriptor));
-        }
-
         await PopulateAsync(authorization, descriptor, cancellationToken);
         await UpdateAsync(authorization, cancellationToken);
     }
@@ -1138,13 +970,8 @@ public class OpenIddictAuthorizationManager<TAuthorization> : IOpenIddictAuthori
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns>The validation error encountered when validating the authorization.</returns>
     public virtual async IAsyncEnumerable<ValidationResult> ValidateAsync(
-        TAuthorization authorization, [EnumeratorCancellation] CancellationToken cancellationToken = default)
+        TAuthorization authorization!!, [EnumeratorCancellation] CancellationToken cancellationToken = default)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         var type = await Store.GetTypeAsync(authorization, cancellationToken);
         if (string.IsNullOrEmpty(type))
         {

src/OpenIddict.Core/Managers/OpenIddictScopeManager.cs

@@ -27,10 +27,10 @@ namespace OpenIddict.Core;
 public class OpenIddictScopeManager<TScope> : IOpenIddictScopeManager where TScope : class
 {
     public OpenIddictScopeManager(
-        IOpenIddictScopeCache<TScope> cache,
-        ILogger<OpenIddictScopeManager<TScope>> logger,
-        IOptionsMonitor<OpenIddictCoreOptions> options,
-        IOpenIddictScopeStoreResolver resolver)
+        IOpenIddictScopeCache<TScope> cache!!,
+        ILogger<OpenIddictScopeManager<TScope>> logger!!,
+        IOptionsMonitor<OpenIddictCoreOptions> options!!,
+        IOpenIddictScopeStoreResolver resolver!!)
     {
         Cache = cache;
         Logger = logger;
@@ -80,15 +80,8 @@ public class OpenIddictScopeManager<TScope> : IOpenIddictScopeManager where TSco
     /// whose result returns the number of scopes that match the specified query.
     /// </returns>
     public virtual ValueTask<long> CountAsync<TResult>(
-        Func<IQueryable<TScope>, IQueryable<TResult>> query, CancellationToken cancellationToken = default)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return Store.CountAsync(query, cancellationToken);
-    }
+        Func<IQueryable<TScope>, IQueryable<TResult>> query!!, CancellationToken cancellationToken = default)
+        => Store.CountAsync(query, cancellationToken);
 
     /// <summary>
     /// Creates a new scope.
@@ -98,13 +91,8 @@ public class OpenIddictScopeManager<TScope> : IOpenIddictScopeManager where TSco
     /// <returns>
     /// A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation.
     /// </returns>
-    public virtual async ValueTask CreateAsync(TScope scope, CancellationToken cancellationToken = default)
+    public virtual async ValueTask CreateAsync(TScope scope!!, CancellationToken cancellationToken = default)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         var results = await GetValidationResultsAsync(scope, cancellationToken);
         if (results.Any(result => result != ValidationResult.Success))
         {
@@ -150,13 +138,8 @@ public class OpenIddictScopeManager<TScope> : IOpenIddictScopeManager where TSco
     /// A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation, whose result returns the scope.
     /// </returns>
     public virtual async ValueTask<TScope> CreateAsync(
-        OpenIddictScopeDescriptor descriptor, CancellationToken cancellationToken = default)
+        OpenIddictScopeDescriptor descriptor!!, CancellationToken cancellationToken = default)
     {
-        if (descriptor is null)
-        {
-            throw new ArgumentNullException(nameof(descriptor));
-        }
-
         var scope = await Store.InstantiateAsync(cancellationToken);
         if (scope is null)
         {
@@ -177,13 +160,8 @@ public class OpenIddictScopeManager<TScope> : IOpenIddictScopeManager where TSco
     /// <returns>
     /// A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation.
     /// </returns>
-    public virtual async ValueTask DeleteAsync(TScope scope, CancellationToken cancellationToken = default)
+    public virtual async ValueTask DeleteAsync(TScope scope!!, CancellationToken cancellationToken = default)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         if (!Options.CurrentValue.DisableEntityCaching)
         {
             await Cache.RemoveAsync(scope, cancellationToken);
@@ -276,7 +254,7 @@ public class OpenIddictScopeManager<TScope> : IOpenIddictScopeManager where TSco
     public virtual IAsyncEnumerable<TScope> FindByNamesAsync(
         ImmutableArray<string> names, CancellationToken cancellationToken = default)
     {
-        if (names.Any(name => string.IsNullOrEmpty(name)))
+        if (names.Any(string.IsNullOrEmpty))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0203), nameof(names));
         }
@@ -361,15 +339,8 @@ public class OpenIddictScopeManager<TScope> : IOpenIddictScopeManager where TSco
     /// whose result returns the first element returned when executing the query.
     /// </returns>
     public virtual ValueTask<TResult?> GetAsync<TResult>(
-        Func<IQueryable<TScope>, IQueryable<TResult>> query, CancellationToken cancellationToken = default)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return GetAsync(static (scopes, query) => query(scopes), query, cancellationToken);
-    }
+        Func<IQueryable<TScope>, IQueryable<TResult>> query!!, CancellationToken cancellationToken = default)
+        => GetAsync(static (scopes, query) => query(scopes), query, cancellationToken);
 
     /// <summary>
     /// Executes the specified query and returns the first element.
@@ -384,16 +355,9 @@ public class OpenIddictScopeManager<TScope> : IOpenIddictScopeManager where TSco
     /// whose result returns the first element returned when executing the query.
     /// </returns>
     public virtual ValueTask<TResult?> GetAsync<TState, TResult>(
-        Func<IQueryable<TScope>, TState, IQueryable<TResult>> query,
+        Func<IQueryable<TScope>, TState, IQueryable<TResult>> query!!,
         TState state, CancellationToken cancellationToken = default)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return Store.GetAsync(query, state, cancellationToken);
-    }
+        => Store.GetAsync(query, state, cancellationToken);
 
     /// <summary>
     /// Retrieves the description associated with a scope.
@@ -404,15 +368,8 @@ public class OpenIddictScopeManager<TScope> : IOpenIddictScopeManager where TSco
     /// A <see cref="ValueTask{TResult}"/> that can be used to monitor the asynchronous operation,
     /// whose result returns the description associated with the specified scope.
     /// </returns>
-    public virtual ValueTask<string?> GetDescriptionAsync(TScope scope, CancellationToken cancellationToken = default)
-    {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
-        return Store.GetDescriptionAsync(scope, cancellationToken);
-    }
+    public virtual ValueTask<string?> GetDescriptionAsync(TScope scope!!, CancellationToken cancellationToken = default)
+        => Store.GetDescriptionAsync(scope, cancellationToken);
 
     /// <summary>
     /// Retrieves the localized descriptions associated with an scope.
@@ -424,21 +381,9 @@ public class OpenIddictScopeManager<TScope> : IOpenIddictScopeManager where TSco
     /// whose result returns all the localized descriptions associated with the scope.
     /// </returns>
     public virtual async ValueTask<ImmutableDictionary<CultureInfo, string>> GetDescriptionsAsync(
-        TScope scope, CancellationToken cancellationToken = default)
-    {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
-        var descriptions = await Store.GetDescriptionsAsync(scope, cancellationToken);
-        if (descriptions is null || descriptions.Count == 0)
-        {
-            return ImmutableDictionary.Create<CultureInfo, string>();
-        }
-
-        return descriptions;
-    }
+        TScope scope!!, CancellationToken cancellationToken = default)
+        => await Store.GetDescriptionsAsync(scope, cancellationToken) is { Count: > 0 } descriptions ?
+            descriptions : ImmutableDictionary.Create<CultureInfo, string>();
 
     /// <summary>
     /// Retrieves the display name associated with a scope.
@@ -449,15 +394,8 @@ public class OpenIddictScopeManager<TScope> : IOpenIddictScopeManager where TSco
     /// A <see cref="ValueTask{TResult}"/> that can be used to monitor the asynchronous operation,
     /// whose result returns the display name associated with the scope.
     /// </returns>
-    public virtual ValueTask<string?> GetDisplayNameAsync(TScope scope, CancellationToken cancellationToken = default)
-    {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
-        return Store.GetDisplayNameAsync(scope, cancellationToken);
-    }
+    public virtual ValueTask<string?> GetDisplayNameAsync(TScope scope!!, CancellationToken cancellationToken = default)
+        => Store.GetDisplayNameAsync(scope, cancellationToken);
 
     /// <summary>
     /// Retrieves the localized display names associated with an scope.
@@ -469,21 +407,9 @@ public class OpenIddictScopeManager<TScope> : IOpenIddictScopeManager where TSco
     /// whose result returns all the localized display names associated with the scope.
     /// </returns>
     public virtual async ValueTask<ImmutableDictionary<CultureInfo, string>> GetDisplayNamesAsync(
-        TScope scope, CancellationToken cancellationToken = default)
-    {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
-        var names = await Store.GetDisplayNamesAsync(scope, cancellationToken);
-        if (names is null || names.Count == 0)
-        {
-            return ImmutableDictionary.Create<CultureInfo, string>();
-        }
-
-        return names;
-    }
+        TScope scope!!, CancellationToken cancellationToken = default)
+        => await Store.GetDisplayNamesAsync(scope, cancellationToken) is { Count: > 0 } names ?
+            names : ImmutableDictionary.Create<CultureInfo, string>();
 
     /// <summary>
     /// Retrieves the unique identifier associated with a scope.
@@ -494,15 +420,8 @@ public class OpenIddictScopeManager<TScope> : IOpenIddictScopeManager where TSco
     /// A <see cref="ValueTask{TResult}"/> that can be used to monitor the asynchronous operation,
     /// whose result returns the unique identifier associated with the scope.
     /// </returns>
-    public virtual ValueTask<string?> GetIdAsync(TScope scope, CancellationToken cancellationToken = default)
-    {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
-        return Store.GetIdAsync(scope, cancellationToken);
-    }
+    public virtual ValueTask<string?> GetIdAsync(TScope scope!!, CancellationToken cancellationToken = default)
+        => Store.GetIdAsync(scope, cancellationToken);
 
     /// <summary>
     /// Retrieves the localized display name associated with an scope
@@ -531,20 +450,10 @@ public class OpenIddictScopeManager<TScope> : IOpenIddictScopeManager where TSco
     /// whose result returns the matching display name associated with the scope.
     /// </returns>
     public virtual async ValueTask<string?> GetLocalizedDisplayNameAsync(
-        TScope scope, CultureInfo culture, CancellationToken cancellationToken = default)
+        TScope scope!!, CultureInfo culture!!, CancellationToken cancellationToken = default)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
-        if (culture is null)
-        {
-            throw new ArgumentNullException(nameof(culture));
-        }
-
         var names = await Store.GetDisplayNamesAsync(scope, cancellationToken);
-        if (names is null || names.IsEmpty)
+        if (names is not { IsEmpty: false })
         {
             return await Store.GetDisplayNameAsync(scope, cancellationToken);
         }
@@ -591,20 +500,10 @@ public class OpenIddictScopeManager<TScope> : IOpenIddictScopeManager where TSco
     /// whose result returns the matching localized description associated with the scope.
     /// </returns>
     public virtual async ValueTask<string?> GetLocalizedDescriptionAsync(
-        TScope scope, CultureInfo culture, CancellationToken cancellationToken = default)
+        TScope scope!!, CultureInfo culture!!, CancellationToken cancellationToken = default)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
-        if (culture is null)
-        {
-            throw new ArgumentNullException(nameof(culture));
-        }
-
         var descriptions = await Store.GetDescriptionsAsync(scope, cancellationToken);
-        if (descriptions is null || descriptions.IsEmpty)
+        if (descriptions is not { IsEmpty: false })
         {
             return await Store.GetDescriptionAsync(scope, cancellationToken);
         }
@@ -633,15 +532,8 @@ public class OpenIddictScopeManager<TScope> : IOpenIddictScopeManager where TSco
     /// A <see cref="ValueTask{TResult}"/> that can be used to monitor the asynchronous operation,
     /// whose result returns the name associated with the specified scope.
     /// </returns>
-    public virtual ValueTask<string?> GetNameAsync(TScope scope, CancellationToken cancellationToken = default)
-    {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
-        return Store.GetNameAsync(scope, cancellationToken);
-    }
+    public virtual ValueTask<string?> GetNameAsync(TScope scope!!, CancellationToken cancellationToken = default)
+        => Store.GetNameAsync(scope, cancellationToken);
 
     /// <summary>
     /// Retrieves the additional properties associated with a scope.
@@ -653,15 +545,8 @@ public class OpenIddictScopeManager<TScope> : IOpenIddictScopeManager where TSco
     /// whose result returns all the additional properties associated with the scope.
     /// </returns>
     public virtual ValueTask<ImmutableDictionary<string, JsonElement>> GetPropertiesAsync(
-        TScope scope, CancellationToken cancellationToken = default)
-    {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
-        return Store.GetPropertiesAsync(scope, cancellationToken);
-    }
+        TScope scope!!, CancellationToken cancellationToken = default)
+        => Store.GetPropertiesAsync(scope, cancellationToken);
 
     /// <summary>
     /// Retrieves the resources associated with a scope.
@@ -673,15 +558,8 @@ public class OpenIddictScopeManager<TScope> : IOpenIddictScopeManager where TSco
     /// whose result returns all the resources associated with the scope.
     /// </returns>
     public virtual ValueTask<ImmutableArray<string>> GetResourcesAsync(
-        TScope scope, CancellationToken cancellationToken = default)
-    {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
-        return Store.GetResourcesAsync(scope, cancellationToken);
-    }
+        TScope scope!!, CancellationToken cancellationToken = default)
+        => Store.GetResourcesAsync(scope, cancellationToken);
 
     /// <summary>
     /// Executes the specified query and returns all the corresponding elements.
@@ -702,15 +580,8 @@ public class OpenIddictScopeManager<TScope> : IOpenIddictScopeManager where TSco
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns>All the elements returned when executing the specified query.</returns>
     public virtual IAsyncEnumerable<TResult> ListAsync<TResult>(
-        Func<IQueryable<TScope>, IQueryable<TResult>> query, CancellationToken cancellationToken = default)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return ListAsync(static (scopes, query) => query(scopes), query, cancellationToken);
-    }
+        Func<IQueryable<TScope>, IQueryable<TResult>> query!!, CancellationToken cancellationToken = default)
+        => ListAsync(static (scopes, query) => query(scopes), query, cancellationToken);
 
     /// <summary>
     /// Executes the specified query and returns all the corresponding elements.
@@ -722,16 +593,9 @@ public class OpenIddictScopeManager<TScope> : IOpenIddictScopeManager where TSco
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns>All the elements returned when executing the specified query.</returns>
     public virtual IAsyncEnumerable<TResult> ListAsync<TState, TResult>(
-        Func<IQueryable<TScope>, TState, IQueryable<TResult>> query,
+        Func<IQueryable<TScope>, TState, IQueryable<TResult>> query!!,
         TState state, CancellationToken cancellationToken = default)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return Store.ListAsync(query, state, cancellationToken);
-    }
+        => Store.ListAsync(query, state, cancellationToken);
 
     /// <summary>
     /// Lists all the resources associated with the specified scopes.
@@ -764,19 +628,9 @@ public class OpenIddictScopeManager<TScope> : IOpenIddictScopeManager where TSco
     /// <returns>
     /// A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation.
     /// </returns>
-    public virtual async ValueTask PopulateAsync(TScope scope,
-        OpenIddictScopeDescriptor descriptor, CancellationToken cancellationToken = default)
+    public virtual async ValueTask PopulateAsync(TScope scope!!,
+        OpenIddictScopeDescriptor descriptor!!, CancellationToken cancellationToken = default)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
-        if (descriptor is null)
-        {
-            throw new ArgumentNullException(nameof(descriptor));
-        }
-
         await Store.SetDescriptionAsync(scope, descriptor.Description, cancellationToken);
         await Store.SetDescriptionsAsync(scope, descriptor.Descriptions.ToImmutableDictionary(), cancellationToken);
         await Store.SetDisplayNameAsync(scope, descriptor.DisplayName, cancellationToken);
@@ -796,19 +650,9 @@ public class OpenIddictScopeManager<TScope> : IOpenIddictScopeManager where TSco
     /// A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation.
     /// </returns>
     public virtual async ValueTask PopulateAsync(
-        OpenIddictScopeDescriptor descriptor,
-        TScope scope, CancellationToken cancellationToken = default)
+        OpenIddictScopeDescriptor descriptor!!,
+        TScope scope!!, CancellationToken cancellationToken = default)
     {
-        if (descriptor is null)
-        {
-            throw new ArgumentNullException(nameof(descriptor));
-        }
-
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         descriptor.Description = await Store.GetDescriptionAsync(scope, cancellationToken);
         descriptor.DisplayName = await Store.GetDisplayNameAsync(scope, cancellationToken);
         descriptor.Name = await Store.GetNameAsync(scope, cancellationToken);
@@ -842,13 +686,8 @@ public class OpenIddictScopeManager<TScope> : IOpenIddictScopeManager where TSco
     /// <returns>
     /// A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation.
     /// </returns>
-    public virtual async ValueTask UpdateAsync(TScope scope, CancellationToken cancellationToken = default)
+    public virtual async ValueTask UpdateAsync(TScope scope!!, CancellationToken cancellationToken = default)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         var results = await GetValidationResultsAsync(scope, cancellationToken);
         if (results.Any(result => result != ValidationResult.Success))
         {
@@ -895,19 +734,9 @@ public class OpenIddictScopeManager<TScope> : IOpenIddictScopeManager where TSco
     /// <returns>
     /// A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation.
     /// </returns>
-    public virtual async ValueTask UpdateAsync(TScope scope,
-        OpenIddictScopeDescriptor descriptor, CancellationToken cancellationToken = default)
+    public virtual async ValueTask UpdateAsync(TScope scope!!,
+        OpenIddictScopeDescriptor descriptor!!, CancellationToken cancellationToken = default)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
-        if (descriptor is null)
-        {
-            throw new ArgumentNullException(nameof(descriptor));
-        }
-
         await PopulateAsync(scope, descriptor, cancellationToken);
         await UpdateAsync(scope, cancellationToken);
     }
@@ -919,12 +748,8 @@ public class OpenIddictScopeManager<TScope> : IOpenIddictScopeManager where TSco
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns>The validation error encountered when validating the scope.</returns>
     public virtual async IAsyncEnumerable<ValidationResult> ValidateAsync(
-        TScope scope, [EnumeratorCancellation] CancellationToken cancellationToken = default)
+        TScope scope!!, [EnumeratorCancellation] CancellationToken cancellationToken = default)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
 
         // Ensure the name is not null or empty, does not contain a
         // space and is not already used for a different scope entity.

src/OpenIddict.Core/Managers/OpenIddictTokenManager.cs

@@ -28,10 +28,10 @@ namespace OpenIddict.Core;
 public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TToken : class
 {
     public OpenIddictTokenManager(
-        IOpenIddictTokenCache<TToken> cache,
-        ILogger<OpenIddictTokenManager<TToken>> logger,
-        IOptionsMonitor<OpenIddictCoreOptions> options,
-        IOpenIddictTokenStoreResolver resolver)
+        IOpenIddictTokenCache<TToken> cache!!,
+        ILogger<OpenIddictTokenManager<TToken>> logger!!,
+        IOptionsMonitor<OpenIddictCoreOptions> options!!,
+        IOpenIddictTokenStoreResolver resolver!!)
     {
         Cache = cache;
         Logger = logger;
@@ -81,15 +81,8 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// whose result returns the number of tokens that match the specified query.
     /// </returns>
     public virtual ValueTask<long> CountAsync<TResult>(
-        Func<IQueryable<TToken>, IQueryable<TResult>> query, CancellationToken cancellationToken = default)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return Store.CountAsync(query, cancellationToken);
-    }
+        Func<IQueryable<TToken>, IQueryable<TResult>> query!!, CancellationToken cancellationToken = default)
+        => Store.CountAsync(query, cancellationToken);
 
     /// <summary>
     /// Creates a new token.
@@ -99,13 +92,8 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// <returns>
     /// A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation.
     /// </returns>
-    public virtual async ValueTask CreateAsync(TToken token, CancellationToken cancellationToken = default)
+    public virtual async ValueTask CreateAsync(TToken token!!, CancellationToken cancellationToken = default)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         // If no status was explicitly specified, assume that the token is valid.
         if (string.IsNullOrEmpty(await Store.GetStatusAsync(token, cancellationToken)))
         {
@@ -165,13 +153,8 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation, whose result returns the token.
     /// </returns>
     public virtual async ValueTask<TToken> CreateAsync(
-        OpenIddictTokenDescriptor descriptor, CancellationToken cancellationToken = default)
+        OpenIddictTokenDescriptor descriptor!!, CancellationToken cancellationToken = default)
     {
-        if (descriptor is null)
-        {
-            throw new ArgumentNullException(nameof(descriptor));
-        }
-
         var token = await Store.InstantiateAsync(cancellationToken);
         if (token is null)
         {
@@ -192,13 +175,8 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// <returns>
     /// A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation.
     /// </returns>
-    public virtual async ValueTask DeleteAsync(TToken token, CancellationToken cancellationToken = default)
+    public virtual async ValueTask DeleteAsync(TToken token!!, CancellationToken cancellationToken = default)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         if (!Options.CurrentValue.DisableEntityCaching)
         {
             await Cache.RemoveAsync(token, cancellationToken);
@@ -579,15 +557,8 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// A <see cref="ValueTask{TResult}"/> that can be used to monitor the asynchronous operation,
     /// whose result returns the application identifier associated with the token.
     /// </returns>
-    public virtual ValueTask<string?> GetApplicationIdAsync(TToken token, CancellationToken cancellationToken = default)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        return Store.GetApplicationIdAsync(token, cancellationToken);
-    }
+    public virtual ValueTask<string?> GetApplicationIdAsync(TToken token!!, CancellationToken cancellationToken = default)
+        => Store.GetApplicationIdAsync(token, cancellationToken);
 
     /// <summary>
     /// Executes the specified query and returns the first element.
@@ -600,15 +571,8 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// whose result returns the first element returned when executing the query.
     /// </returns>
     public virtual ValueTask<TResult?> GetAsync<TResult>(
-        Func<IQueryable<TToken>, IQueryable<TResult>> query, CancellationToken cancellationToken = default)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return GetAsync(static (tokens, query) => query(tokens), query, cancellationToken);
-    }
+        Func<IQueryable<TToken>, IQueryable<TResult>> query!!, CancellationToken cancellationToken = default)
+        => GetAsync(static (tokens, query) => query(tokens), query, cancellationToken);
 
     /// <summary>
     /// Executes the specified query and returns the first element.
@@ -623,16 +587,9 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// whose result returns the first element returned when executing the query.
     /// </returns>
     public virtual ValueTask<TResult?> GetAsync<TState, TResult>(
-        Func<IQueryable<TToken>, TState, IQueryable<TResult>> query,
+        Func<IQueryable<TToken>, TState, IQueryable<TResult>> query!!,
         TState state, CancellationToken cancellationToken = default)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return Store.GetAsync(query, state, cancellationToken);
-    }
+        => Store.GetAsync(query, state, cancellationToken);
 
     /// <summary>
     /// Retrieves the optional authorization identifier associated with a token.
@@ -643,15 +600,8 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// A <see cref="ValueTask{TResult}"/> that can be used to monitor the asynchronous operation,
     /// whose result returns the authorization identifier associated with the token.
     /// </returns>
-    public virtual ValueTask<string?> GetAuthorizationIdAsync(TToken token, CancellationToken cancellationToken = default)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        return Store.GetAuthorizationIdAsync(token, cancellationToken);
-    }
+    public virtual ValueTask<string?> GetAuthorizationIdAsync(TToken token!!, CancellationToken cancellationToken = default)
+        => Store.GetAuthorizationIdAsync(token, cancellationToken);
 
     /// <summary>
     /// Retrieves the creation date associated with a token.
@@ -662,15 +612,8 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// A <see cref="ValueTask{TResult}"/> that can be used to monitor the asynchronous operation,
     /// whose result returns the creation date associated with the specified token.
     /// </returns>
-    public virtual ValueTask<DateTimeOffset?> GetCreationDateAsync(TToken token, CancellationToken cancellationToken = default)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        return Store.GetCreationDateAsync(token, cancellationToken);
-    }
+    public virtual ValueTask<DateTimeOffset?> GetCreationDateAsync(TToken token!!, CancellationToken cancellationToken = default)
+        => Store.GetCreationDateAsync(token, cancellationToken);
 
     /// <summary>
     /// Retrieves the expiration date associated with a token.
@@ -681,15 +624,8 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// A <see cref="ValueTask{TResult}"/> that can be used to monitor the asynchronous operation,
     /// whose result returns the expiration date associated with the specified token.
     /// </returns>
-    public virtual ValueTask<DateTimeOffset?> GetExpirationDateAsync(TToken token, CancellationToken cancellationToken = default)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        return Store.GetExpirationDateAsync(token, cancellationToken);
-    }
+    public virtual ValueTask<DateTimeOffset?> GetExpirationDateAsync(TToken token!!, CancellationToken cancellationToken = default)
+        => Store.GetExpirationDateAsync(token, cancellationToken);
 
     /// <summary>
     /// Retrieves the unique identifier associated with a token.
@@ -700,15 +636,8 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// A <see cref="ValueTask{TResult}"/> that can be used to monitor the asynchronous operation,
     /// whose result returns the unique identifier associated with the token.
     /// </returns>
-    public virtual ValueTask<string?> GetIdAsync(TToken token, CancellationToken cancellationToken = default)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        return Store.GetIdAsync(token, cancellationToken);
-    }
+    public virtual ValueTask<string?> GetIdAsync(TToken token!!, CancellationToken cancellationToken = default)
+        => Store.GetIdAsync(token, cancellationToken);
 
     /// <summary>
     /// Retrieves the payload associated with a token.
@@ -719,15 +648,8 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// A <see cref="ValueTask{TResult}"/> that can be used to monitor the asynchronous operation,
     /// whose result returns the payload associated with the specified token.
     /// </returns>
-    public virtual ValueTask<string?> GetPayloadAsync(TToken token, CancellationToken cancellationToken = default)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        return Store.GetPayloadAsync(token, cancellationToken);
-    }
+    public virtual ValueTask<string?> GetPayloadAsync(TToken token!!, CancellationToken cancellationToken = default)
+        => Store.GetPayloadAsync(token, cancellationToken);
 
     /// <summary>
     /// Retrieves the additional properties associated with a token.
@@ -739,15 +661,8 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// whose result returns all the additional properties associated with the token.
     /// </returns>
     public virtual ValueTask<ImmutableDictionary<string, JsonElement>> GetPropertiesAsync(
-        TToken token, CancellationToken cancellationToken = default)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        return Store.GetPropertiesAsync(token, cancellationToken);
-    }
+        TToken token!!, CancellationToken cancellationToken = default)
+        => Store.GetPropertiesAsync(token, cancellationToken);
 
     /// <summary>
     /// Retrieves the redemption date associated with a token.
@@ -758,15 +673,8 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// A <see cref="ValueTask{TResult}"/> that can be used to monitor the asynchronous operation,
     /// whose result returns the redemption date associated with the specified token.
     /// </returns>
-    public virtual ValueTask<DateTimeOffset?> GetRedemptionDateAsync(TToken token, CancellationToken cancellationToken = default)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        return Store.GetRedemptionDateAsync(token, cancellationToken);
-    }
+    public virtual ValueTask<DateTimeOffset?> GetRedemptionDateAsync(TToken token!!, CancellationToken cancellationToken = default)
+        => Store.GetRedemptionDateAsync(token, cancellationToken);
 
     /// <summary>
     /// Retrieves the reference identifier associated with a token.
@@ -779,15 +687,8 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// A <see cref="ValueTask{TResult}"/> that can be used to monitor the asynchronous operation,
     /// whose result returns the reference identifier associated with the specified token.
     /// </returns>
-    public virtual ValueTask<string?> GetReferenceIdAsync(TToken token, CancellationToken cancellationToken = default)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        return Store.GetReferenceIdAsync(token, cancellationToken);
-    }
+    public virtual ValueTask<string?> GetReferenceIdAsync(TToken token!!, CancellationToken cancellationToken = default)
+        => Store.GetReferenceIdAsync(token, cancellationToken);
 
     /// <summary>
     /// Retrieves the status associated with a token.
@@ -798,15 +699,8 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// A <see cref="ValueTask{TResult}"/> that can be used to monitor the asynchronous operation,
     /// whose result returns the status associated with the specified token.
     /// </returns>
-    public virtual ValueTask<string?> GetStatusAsync(TToken token, CancellationToken cancellationToken = default)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        return Store.GetStatusAsync(token, cancellationToken);
-    }
+    public virtual ValueTask<string?> GetStatusAsync(TToken token!!, CancellationToken cancellationToken = default)
+        => Store.GetStatusAsync(token, cancellationToken);
 
     /// <summary>
     /// Retrieves the subject associated with a token.
@@ -817,15 +711,8 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// A <see cref="ValueTask{TResult}"/> that can be used to monitor the asynchronous operation,
     /// whose result returns the subject associated with the specified token.
     /// </returns>
-    public virtual ValueTask<string?> GetSubjectAsync(TToken token, CancellationToken cancellationToken = default)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        return Store.GetSubjectAsync(token, cancellationToken);
-    }
+    public virtual ValueTask<string?> GetSubjectAsync(TToken token!!, CancellationToken cancellationToken = default)
+        => Store.GetSubjectAsync(token, cancellationToken);
 
     /// <summary>
     /// Retrieves the token type associated with a token.
@@ -836,15 +723,8 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// A <see cref="ValueTask{TResult}"/> that can be used to monitor the asynchronous operation,
     /// whose result returns the token type associated with the specified token.
     /// </returns>
-    public virtual ValueTask<string?> GetTypeAsync(TToken token, CancellationToken cancellationToken = default)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        return Store.GetTypeAsync(token, cancellationToken);
-    }
+    public virtual ValueTask<string?> GetTypeAsync(TToken token!!, CancellationToken cancellationToken = default)
+        => Store.GetTypeAsync(token, cancellationToken);
 
     /// <summary>
     /// Determines whether a given token has the specified status.
@@ -853,13 +733,8 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// <param name="status">The expected status.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns><c>true</c> if the token has the specified status, <c>false</c> otherwise.</returns>
-    public virtual async ValueTask<bool> HasStatusAsync(TToken token, string status, CancellationToken cancellationToken = default)
+    public virtual async ValueTask<bool> HasStatusAsync(TToken token!!, string status, CancellationToken cancellationToken = default)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         if (string.IsNullOrEmpty(status))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0199), nameof(status));
@@ -875,13 +750,8 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// <param name="type">The expected type.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns><c>true</c> if the token has the specified type, <c>false</c> otherwise.</returns>
-    public virtual async ValueTask<bool> HasTypeAsync(TToken token, string type, CancellationToken cancellationToken = default)
+    public virtual async ValueTask<bool> HasTypeAsync(TToken token!!, string type, CancellationToken cancellationToken = default)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         if (string.IsNullOrEmpty(type))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0200), nameof(type));
@@ -897,13 +767,8 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// <param name="types">The expected types.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns><c>true</c> if the token has any of the specified types, <c>false</c> otherwise.</returns>
-    public virtual async ValueTask<bool> HasTypeAsync(TToken token, ImmutableArray<string> types, CancellationToken cancellationToken = default)
+    public virtual async ValueTask<bool> HasTypeAsync(TToken token!!, ImmutableArray<string> types, CancellationToken cancellationToken = default)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         var type = await Store.GetTypeAsync(token, cancellationToken);
         if (string.IsNullOrEmpty(type))
         {
@@ -940,15 +805,8 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns>All the elements returned when executing the specified query.</returns>
     public virtual IAsyncEnumerable<TResult> ListAsync<TResult>(
-        Func<IQueryable<TToken>, IQueryable<TResult>> query, CancellationToken cancellationToken = default)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return ListAsync(static (tokens, query) => query(tokens), query, cancellationToken);
-    }
+        Func<IQueryable<TToken>, IQueryable<TResult>> query!!, CancellationToken cancellationToken = default)
+        => ListAsync(static (tokens, query) => query(tokens), query, cancellationToken);
 
     /// <summary>
     /// Executes the specified query and returns all the corresponding elements.
@@ -960,16 +818,9 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns>All the elements returned when executing the specified query.</returns>
     public virtual IAsyncEnumerable<TResult> ListAsync<TState, TResult>(
-        Func<IQueryable<TToken>, TState, IQueryable<TResult>> query,
+        Func<IQueryable<TToken>, TState, IQueryable<TResult>> query!!,
         TState state, CancellationToken cancellationToken = default)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return Store.ListAsync(query, state, cancellationToken);
-    }
+        => Store.ListAsync(query, state, cancellationToken);
 
     /// <summary>
     /// Populates the token using the specified descriptor.
@@ -980,19 +831,9 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// <returns>
     /// A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation.
     /// </returns>
-    public virtual async ValueTask PopulateAsync(TToken token,
-        OpenIddictTokenDescriptor descriptor, CancellationToken cancellationToken = default)
+    public virtual async ValueTask PopulateAsync(TToken token!!,
+        OpenIddictTokenDescriptor descriptor!!, CancellationToken cancellationToken = default)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        if (descriptor is null)
-        {
-            throw new ArgumentNullException(nameof(descriptor));
-        }
-
         await Store.SetApplicationIdAsync(token, descriptor.ApplicationId, cancellationToken);
         await Store.SetAuthorizationIdAsync(token, descriptor.AuthorizationId, cancellationToken);
         await Store.SetCreationDateAsync(token, descriptor.CreationDate, cancellationToken);
@@ -1016,19 +857,9 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation.
     /// </returns>
     public virtual async ValueTask PopulateAsync(
-        OpenIddictTokenDescriptor descriptor,
-        TToken token, CancellationToken cancellationToken = default)
+        OpenIddictTokenDescriptor descriptor!!,
+        TToken token!!, CancellationToken cancellationToken = default)
     {
-        if (descriptor is null)
-        {
-            throw new ArgumentNullException(nameof(descriptor));
-        }
-
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         descriptor.ApplicationId = await Store.GetApplicationIdAsync(token, cancellationToken);
         descriptor.AuthorizationId = await Store.GetAuthorizationIdAsync(token, cancellationToken);
         descriptor.CreationDate = await Store.GetCreationDateAsync(token, cancellationToken);
@@ -1058,19 +889,15 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// </returns>
     public virtual ValueTask PruneAsync(DateTimeOffset threshold, CancellationToken cancellationToken = default)
         => Store.PruneAsync(threshold, cancellationToken);
+
     /// <summary>
     /// Tries to redeem a token.
     /// </summary>
     /// <param name="token">The token to redeem.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns><c>true</c> if the token was successfully redemeed, <c>false</c> otherwise.</returns>
-    public virtual async ValueTask<bool> TryRedeemAsync(TToken token, CancellationToken cancellationToken = default)
+    public virtual async ValueTask<bool> TryRedeemAsync(TToken token!!, CancellationToken cancellationToken = default)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         // If the token doesn't have a redemption date attached, this likely means it's
         // the first time the token is redeemed. In this case, attach the current date.
         if (await Store.GetRedemptionDateAsync(token, cancellationToken) is null)
@@ -1110,13 +937,8 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// <param name="token">The token to reject.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns><c>true</c> if the token was successfully redemeed, <c>false</c> otherwise.</returns>
-    public virtual async ValueTask<bool> TryRejectAsync(TToken token, CancellationToken cancellationToken = default)
+    public virtual async ValueTask<bool> TryRejectAsync(TToken token!!, CancellationToken cancellationToken = default)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         await Store.SetStatusAsync(token, Statuses.Rejected, cancellationToken);
 
         try
@@ -1149,13 +971,8 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// <param name="token">The token to revoke.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns><c>true</c> if the token was successfully revoked, <c>false</c> otherwise.</returns>
-    public virtual async ValueTask<bool> TryRevokeAsync(TToken token, CancellationToken cancellationToken = default)
+    public virtual async ValueTask<bool> TryRevokeAsync(TToken token!!, CancellationToken cancellationToken = default)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         await Store.SetStatusAsync(token, Statuses.Revoked, cancellationToken);
 
         try
@@ -1190,13 +1007,8 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// <returns>
     /// A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation.
     /// </returns>
-    public virtual async ValueTask UpdateAsync(TToken token, CancellationToken cancellationToken = default)
+    public virtual async ValueTask UpdateAsync(TToken token!!, CancellationToken cancellationToken = default)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         var results = await GetValidationResultsAsync(token, cancellationToken);
         if (results.Any(result => result != ValidationResult.Success))
         {
@@ -1243,18 +1055,9 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// <returns>
     /// A <see cref="ValueTask"/> that can be used to monitor the asynchronous operation.
     /// </returns>
-    public virtual async ValueTask UpdateAsync(TToken token,
-        OpenIddictTokenDescriptor descriptor, CancellationToken cancellationToken = default)
+    public virtual async ValueTask UpdateAsync(TToken token!!,
+        OpenIddictTokenDescriptor descriptor!!, CancellationToken cancellationToken = default)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        if (descriptor is null)
-        {
-            throw new ArgumentNullException(nameof(descriptor));
-        }
 
         // Store the original reference identifier for later comparison.
         var comparand = await Store.GetReferenceIdAsync(token, cancellationToken);
@@ -1278,13 +1081,8 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns>The validation error encountered when validating the token.</returns>
     public virtual async IAsyncEnumerable<ValidationResult> ValidateAsync(
-        TToken token, [EnumeratorCancellation] CancellationToken cancellationToken = default)
+        TToken token!!, [EnumeratorCancellation] CancellationToken cancellationToken = default)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         // If a reference identifier was associated with the token,
         // ensure it's not already used for a different token.
         var identifier = await Store.GetReferenceIdAsync(token, cancellationToken);
@@ -1334,7 +1132,7 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
         // Compute the digest of the generated identifier and use it as the hashed identifier of the reference token.
         // Doing that prevents token identifiers stolen from the database from being used as valid reference tokens.
         using var algorithm = SHA256.Create();
-        return new ValueTask<string>(Convert.ToBase64String(algorithm.ComputeHash(Encoding.UTF8.GetBytes(identifier))));
+        return new(Convert.ToBase64String(algorithm.ComputeHash(Encoding.UTF8.GetBytes(identifier))));
     }
 
     /// <inheritdoc/>

src/OpenIddict.Core/OpenIddictCoreBuilder.cs

@@ -20,8 +20,8 @@ public class OpenIddictCoreBuilder
     /// Initializes a new instance of <see cref="OpenIddictCoreBuilder"/>.
     /// </summary>
     /// <param name="services">The services collection.</param>
-    public OpenIddictCoreBuilder(IServiceCollection services)
-        => Services = services ?? throw new ArgumentNullException(nameof(services));
+    public OpenIddictCoreBuilder(IServiceCollection services!!)
+        => Services = services;
 
     /// <summary>
     /// Gets the services collection.
@@ -35,13 +35,8 @@ public class OpenIddictCoreBuilder
     /// <param name="configuration">The delegate used to configure the OpenIddict options.</param>
     /// <remarks>This extension can be safely called multiple times.</remarks>
     /// <returns>The <see cref="OpenIddictCoreBuilder"/>.</returns>
-    public OpenIddictCoreBuilder Configure(Action<OpenIddictCoreOptions> configuration)
+    public OpenIddictCoreBuilder Configure(Action<OpenIddictCoreOptions> configuration!!)
     {
-        if (configuration is null)
-        {
-            throw new ArgumentNullException(nameof(configuration));
-        }
-
         Services.Configure(configuration);
 
         return this;
@@ -69,13 +64,8 @@ public class OpenIddictCoreBuilder
     /// <param name="type">The type of the custom store.</param>
     /// <param name="lifetime">The lifetime of the registered service.</param>
     /// <returns>The <see cref="OpenIddictCoreBuilder"/>.</returns>
-    public OpenIddictCoreBuilder AddApplicationStore(Type type, ServiceLifetime lifetime = ServiceLifetime.Scoped)
+    public OpenIddictCoreBuilder AddApplicationStore(Type type!!, ServiceLifetime lifetime = ServiceLifetime.Scoped)
     {
-        if (type is null)
-        {
-            throw new ArgumentNullException(nameof(type));
-        }
-
         var root = OpenIddictHelpers.FindGenericBaseType(type, typeof(IOpenIddictApplicationStore<>));
         if (root is null)
         {
@@ -125,13 +115,8 @@ public class OpenIddictCoreBuilder
     /// <param name="type">The type of the custom store.</param>
     /// <param name="lifetime">The lifetime of the registered service.</param>
     /// <returns>The <see cref="OpenIddictCoreBuilder"/>.</returns>
-    public OpenIddictCoreBuilder AddAuthorizationStore(Type type, ServiceLifetime lifetime = ServiceLifetime.Scoped)
+    public OpenIddictCoreBuilder AddAuthorizationStore(Type type!!, ServiceLifetime lifetime = ServiceLifetime.Scoped)
     {
-        if (type is null)
-        {
-            throw new ArgumentNullException(nameof(type));
-        }
-
         var root = OpenIddictHelpers.FindGenericBaseType(type, typeof(IOpenIddictAuthorizationStore<>));
         if (root is null)
         {
@@ -181,13 +166,8 @@ public class OpenIddictCoreBuilder
     /// <param name="type">The type of the custom store.</param>
     /// <param name="lifetime">The lifetime of the registered service.</param>
     /// <returns>The <see cref="OpenIddictCoreBuilder"/>.</returns>
-    public OpenIddictCoreBuilder AddScopeStore(Type type, ServiceLifetime lifetime = ServiceLifetime.Scoped)
+    public OpenIddictCoreBuilder AddScopeStore(Type type!!, ServiceLifetime lifetime = ServiceLifetime.Scoped)
     {
-        if (type is null)
-        {
-            throw new ArgumentNullException(nameof(type));
-        }
-
         var root = OpenIddictHelpers.FindGenericBaseType(type, typeof(IOpenIddictScopeStore<>));
         if (root is null)
         {
@@ -237,13 +217,8 @@ public class OpenIddictCoreBuilder
     /// <param name="type">The type of the custom store.</param>
     /// <param name="lifetime">The lifetime of the registered service.</param>
     /// <returns>The <see cref="OpenIddictCoreBuilder"/>.</returns>
-    public OpenIddictCoreBuilder AddTokenStore(Type type, ServiceLifetime lifetime = ServiceLifetime.Scoped)
+    public OpenIddictCoreBuilder AddTokenStore(Type type!!, ServiceLifetime lifetime = ServiceLifetime.Scoped)
     {
-        if (type is null)
-        {
-            throw new ArgumentNullException(nameof(type));
-        }
-
         var root = OpenIddictHelpers.FindGenericBaseType(type, typeof(IOpenIddictTokenStore<>));
         if (root is null)
         {
@@ -291,13 +266,8 @@ public class OpenIddictCoreBuilder
     /// </summary>
     /// <param name="type">The type of the custom manager.</param>
     /// <returns>The <see cref="OpenIddictCoreBuilder"/>.</returns>
-    public OpenIddictCoreBuilder ReplaceApplicationManager(Type type)
+    public OpenIddictCoreBuilder ReplaceApplicationManager(Type type!!)
     {
-        if (type is null)
-        {
-            throw new ArgumentNullException(nameof(type));
-        }
-
         var root = OpenIddictHelpers.FindGenericBaseType(type, typeof(OpenIddictApplicationManager<>));
         if (root is null)
         {
@@ -348,13 +318,8 @@ public class OpenIddictCoreBuilder
     /// <param name="lifetime">The lifetime of the registered service.</param>
     /// <returns>The <see cref="OpenIddictCoreBuilder"/>.</returns>
     public OpenIddictCoreBuilder ReplaceApplicationStoreResolver(
-        Type type, ServiceLifetime lifetime = ServiceLifetime.Scoped)
+        Type type!!, ServiceLifetime lifetime = ServiceLifetime.Scoped)
     {
-        if (type is null)
-        {
-            throw new ArgumentNullException(nameof(type));
-        }
-
         if (!typeof(IOpenIddictApplicationStoreResolver).IsAssignableFrom(type))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0232), nameof(type));
@@ -385,13 +350,8 @@ public class OpenIddictCoreBuilder
     /// </summary>
     /// <param name="type">The type of the custom manager.</param>
     /// <returns>The <see cref="OpenIddictCoreBuilder"/>.</returns>
-    public OpenIddictCoreBuilder ReplaceAuthorizationManager(Type type)
+    public OpenIddictCoreBuilder ReplaceAuthorizationManager(Type type!!)
     {
-        if (type is null)
-        {
-            throw new ArgumentNullException(nameof(type));
-        }
-
         var root = OpenIddictHelpers.FindGenericBaseType(type, typeof(OpenIddictAuthorizationManager<>));
         if (root is null)
         {
@@ -442,13 +402,8 @@ public class OpenIddictCoreBuilder
     /// <param name="lifetime">The lifetime of the registered service.</param>
     /// <returns>The <see cref="OpenIddictCoreBuilder"/>.</returns>
     public OpenIddictCoreBuilder ReplaceAuthorizationStoreResolver(
-        Type type, ServiceLifetime lifetime = ServiceLifetime.Scoped)
+        Type type!!, ServiceLifetime lifetime = ServiceLifetime.Scoped)
     {
-        if (type is null)
-        {
-            throw new ArgumentNullException(nameof(type));
-        }
-
         if (!typeof(IOpenIddictAuthorizationStoreResolver).IsAssignableFrom(type))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0232), nameof(type));
@@ -479,13 +434,8 @@ public class OpenIddictCoreBuilder
     /// </summary>
     /// <param name="type">The type of the custom manager.</param>
     /// <returns>The <see cref="OpenIddictCoreBuilder"/>.</returns>
-    public OpenIddictCoreBuilder ReplaceScopeManager(Type type)
+    public OpenIddictCoreBuilder ReplaceScopeManager(Type type!!)
     {
-        if (type is null)
-        {
-            throw new ArgumentNullException(nameof(type));
-        }
-
         var root = OpenIddictHelpers.FindGenericBaseType(type, typeof(OpenIddictScopeManager<>));
         if (root is null)
         {
@@ -536,13 +486,8 @@ public class OpenIddictCoreBuilder
     /// <param name="lifetime">The lifetime of the registered service.</param>
     /// <returns>The <see cref="OpenIddictCoreBuilder"/>.</returns>
     public OpenIddictCoreBuilder ReplaceScopeStoreResolver(
-        Type type, ServiceLifetime lifetime = ServiceLifetime.Scoped)
+        Type type!!, ServiceLifetime lifetime = ServiceLifetime.Scoped)
     {
-        if (type is null)
-        {
-            throw new ArgumentNullException(nameof(type));
-        }
-
         if (!typeof(IOpenIddictScopeStoreResolver).IsAssignableFrom(type))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0232), nameof(type));
@@ -573,13 +518,8 @@ public class OpenIddictCoreBuilder
     /// </summary>
     /// <param name="type">The type of the custom manager.</param>
     /// <returns>The <see cref="OpenIddictCoreBuilder"/>.</returns>
-    public OpenIddictCoreBuilder ReplaceTokenManager(Type type)
+    public OpenIddictCoreBuilder ReplaceTokenManager(Type type!!)
     {
-        if (type is null)
-        {
-            throw new ArgumentNullException(nameof(type));
-        }
-
         var root = OpenIddictHelpers.FindGenericBaseType(type, typeof(OpenIddictTokenManager<>));
         if (root is null)
         {
@@ -630,13 +570,8 @@ public class OpenIddictCoreBuilder
     /// <param name="lifetime">The lifetime of the registered service.</param>
     /// <returns>The <see cref="OpenIddictCoreBuilder"/>.</returns>
     public OpenIddictCoreBuilder ReplaceTokenStoreResolver(
-        Type type, ServiceLifetime lifetime = ServiceLifetime.Scoped)
+        Type type!!, ServiceLifetime lifetime = ServiceLifetime.Scoped)
     {
-        if (type is null)
-        {
-            throw new ArgumentNullException(nameof(type));
-        }
-
         if (!typeof(IOpenIddictTokenStoreResolver).IsAssignableFrom(type))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0232), nameof(type));
@@ -679,13 +614,8 @@ public class OpenIddictCoreBuilder
     /// </summary>
     /// <param name="type">The application entity type.</param>
     /// <returns>The <see cref="OpenIddictCoreBuilder"/>.</returns>
-    public OpenIddictCoreBuilder SetDefaultApplicationEntity(Type type)
+    public OpenIddictCoreBuilder SetDefaultApplicationEntity(Type type!!)
     {
-        if (type is null)
-        {
-            throw new ArgumentNullException(nameof(type));
-        }
-
         if (type.IsValueType)
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0232), nameof(type));
@@ -706,13 +636,8 @@ public class OpenIddictCoreBuilder
     /// </summary>
     /// <param name="type">The authorization entity type.</param>
     /// <returns>The <see cref="OpenIddictCoreBuilder"/>.</returns>
-    public OpenIddictCoreBuilder SetDefaultAuthorizationEntity(Type type)
+    public OpenIddictCoreBuilder SetDefaultAuthorizationEntity(Type type!!)
     {
-        if (type is null)
-        {
-            throw new ArgumentNullException(nameof(type));
-        }
-
         if (type.IsValueType)
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0232), nameof(type));
@@ -733,13 +658,8 @@ public class OpenIddictCoreBuilder
     /// </summary>
     /// <param name="type">The scope entity type.</param>
     /// <returns>The <see cref="OpenIddictCoreBuilder"/>.</returns>
-    public OpenIddictCoreBuilder SetDefaultScopeEntity(Type type)
+    public OpenIddictCoreBuilder SetDefaultScopeEntity(Type type!!)
     {
-        if (type is null)
-        {
-            throw new ArgumentNullException(nameof(type));
-        }
-
         if (type.IsValueType)
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0232), nameof(type));
@@ -760,13 +680,8 @@ public class OpenIddictCoreBuilder
     /// </summary>
     /// <param name="type">The token entity type.</param>
     /// <returns>The <see cref="OpenIddictCoreBuilder"/>.</returns>
-    public OpenIddictCoreBuilder SetDefaultTokenEntity(Type type)
+    public OpenIddictCoreBuilder SetDefaultTokenEntity(Type type!!)
     {
-        if (type is null)
-        {
-            throw new ArgumentNullException(nameof(type));
-        }
-
         if (type.IsValueType)
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0232), nameof(type));

src/OpenIddict.Core/OpenIddictCoreExtensions.cs

@@ -22,13 +22,8 @@ public static class OpenIddictCoreExtensions
     /// <param name="builder">The services builder used by OpenIddict to register new services.</param>
     /// <remarks>This extension can be safely called multiple times.</remarks>
     /// <returns>The <see cref="OpenIddictBuilder"/>.</returns>
-    public static OpenIddictCoreBuilder AddCore(this OpenIddictBuilder builder)
+    public static OpenIddictCoreBuilder AddCore(this OpenIddictBuilder builder!!)
     {
-        if (builder is null)
-        {
-            throw new ArgumentNullException(nameof(builder));
-        }
-
         builder.Services.AddLogging();
         builder.Services.AddMemoryCache();
         builder.Services.AddOptions();
@@ -106,18 +101,8 @@ public static class OpenIddictCoreExtensions
     /// <param name="configuration">The configuration delegate used to configure the core services.</param>
     /// <remarks>This extension can be safely called multiple times.</remarks>
     /// <returns>The <see cref="OpenIddictBuilder"/>.</returns>
-    public static OpenIddictBuilder AddCore(this OpenIddictBuilder builder, Action<OpenIddictCoreBuilder> configuration)
+    public static OpenIddictBuilder AddCore(this OpenIddictBuilder builder!!, Action<OpenIddictCoreBuilder> configuration!!)
     {
-        if (builder is null)
-        {
-            throw new ArgumentNullException(nameof(builder));
-        }
-
-        if (configuration is null)
-        {
-            throw new ArgumentNullException(nameof(configuration));
-        }
-
         configuration(builder.AddCore());
 
         return builder;

src/OpenIddict.Core/Resolvers/OpenIddictApplicationStoreResolver.cs

@@ -9,7 +9,7 @@ public class OpenIddictApplicationStoreResolver : IOpenIddictApplicationStoreRes
 {
     private readonly IServiceProvider _provider;
 
-    public OpenIddictApplicationStoreResolver(IServiceProvider provider)
+    public OpenIddictApplicationStoreResolver(IServiceProvider provider!!)
         => _provider = provider;
 
     /// <summary>

src/OpenIddict.Core/Resolvers/OpenIddictAuthorizationStoreResolver.cs

@@ -9,7 +9,7 @@ public class OpenIddictAuthorizationStoreResolver : IOpenIddictAuthorizationStor
 {
     private readonly IServiceProvider _provider;
 
-    public OpenIddictAuthorizationStoreResolver(IServiceProvider provider)
+    public OpenIddictAuthorizationStoreResolver(IServiceProvider provider!!)
         => _provider = provider;
 
     /// <summary>

src/OpenIddict.Core/Resolvers/OpenIddictScopeStoreResolver.cs

@@ -9,7 +9,7 @@ public class OpenIddictScopeStoreResolver : IOpenIddictScopeStoreResolver
 {
     private readonly IServiceProvider _provider;
 
-    public OpenIddictScopeStoreResolver(IServiceProvider provider)
+    public OpenIddictScopeStoreResolver(IServiceProvider provider!!)
         => _provider = provider;
 
     /// <summary>

src/OpenIddict.Core/Resolvers/OpenIddictTokenStoreResolver.cs

@@ -9,7 +9,7 @@ public class OpenIddictTokenStoreResolver : IOpenIddictTokenStoreResolver
 {
     private readonly IServiceProvider _provider;
 
-    public OpenIddictTokenStoreResolver(IServiceProvider provider)
+    public OpenIddictTokenStoreResolver(IServiceProvider provider!!)
         => _provider = provider;
 
     /// <summary>

src/OpenIddict.EntityFramework/OpenIddictEntityFrameworkBuilder.cs

@@ -21,8 +21,8 @@ public class OpenIddictEntityFrameworkBuilder
     /// Initializes a new instance of <see cref="OpenIddictEntityFrameworkBuilder"/>.
     /// </summary>
     /// <param name="services">The services collection.</param>
-    public OpenIddictEntityFrameworkBuilder(IServiceCollection services)
-        => Services = services ?? throw new ArgumentNullException(nameof(services));
+    public OpenIddictEntityFrameworkBuilder(IServiceCollection services!!)
+        => Services = services;
 
     /// <summary>
     /// Gets the services collection.
@@ -36,13 +36,8 @@ public class OpenIddictEntityFrameworkBuilder
     /// <param name="configuration">The delegate used to configure the OpenIddict options.</param>
     /// <remarks>This extension can be safely called multiple times.</remarks>
     /// <returns>The <see cref="OpenIddictEntityFrameworkBuilder"/>.</returns>
-    public OpenIddictEntityFrameworkBuilder Configure(Action<OpenIddictEntityFrameworkOptions> configuration)
+    public OpenIddictEntityFrameworkBuilder Configure(Action<OpenIddictEntityFrameworkOptions> configuration!!)
     {
-        if (configuration is null)
-        {
-            throw new ArgumentNullException(nameof(configuration));
-        }
-
         Services.Configure(configuration);
 
         return this;
@@ -94,13 +89,8 @@ public class OpenIddictEntityFrameworkBuilder
     /// </summary>
     /// <param name="type">The type of the <see cref="DbContext"/> used by OpenIddict.</param>
     /// <returns>The <see cref="OpenIddictEntityFrameworkBuilder"/>.</returns>
-    public OpenIddictEntityFrameworkBuilder UseDbContext(Type type)
+    public OpenIddictEntityFrameworkBuilder UseDbContext(Type type!!)
     {
-        if (type is null)
-        {
-            throw new ArgumentNullException(nameof(type));
-        }
-
         if (!typeof(DbContext).IsAssignableFrom(type))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0232), nameof(type));

src/OpenIddict.EntityFramework/OpenIddictEntityFrameworkExtensions.cs

@@ -22,13 +22,8 @@ public static class OpenIddictEntityFrameworkExtensions
     /// <param name="builder">The services builder used by OpenIddict to register new services.</param>
     /// <remarks>This extension can be safely called multiple times.</remarks>
     /// <returns>The <see cref="OpenIddictEntityFrameworkBuilder"/>.</returns>
-    public static OpenIddictEntityFrameworkBuilder UseEntityFramework(this OpenIddictCoreBuilder builder)
+    public static OpenIddictEntityFrameworkBuilder UseEntityFramework(this OpenIddictCoreBuilder builder!!)
     {
-        if (builder is null)
-        {
-            throw new ArgumentNullException(nameof(builder));
-        }
-
         // Since Entity Framework 6.x may be used with databases performing case-insensitive
         // or culture-sensitive comparisons, ensure the additional filtering logic is enforced
         // in case case-sensitive stores were registered before this extension was called.
@@ -66,18 +61,8 @@ public static class OpenIddictEntityFrameworkExtensions
     /// <remarks>This extension can be safely called multiple times.</remarks>
     /// <returns>The <see cref="OpenIddictCoreBuilder"/>.</returns>
     public static OpenIddictCoreBuilder UseEntityFramework(
-        this OpenIddictCoreBuilder builder, Action<OpenIddictEntityFrameworkBuilder> configuration)
+        this OpenIddictCoreBuilder builder!!, Action<OpenIddictEntityFrameworkBuilder> configuration!!)
     {
-        if (builder is null)
-        {
-            throw new ArgumentNullException(nameof(builder));
-        }
-
-        if (configuration is null)
-        {
-            throw new ArgumentNullException(nameof(configuration));
-        }
-
         configuration(builder.UseEntityFramework());
 
         return builder;

src/OpenIddict.EntityFramework/OpenIddictEntityFrameworkHelpers.cs

@@ -38,18 +38,13 @@ public static class OpenIddictEntityFrameworkHelpers
     /// </remarks>
     /// <param name="builder">The builder used to configure the Entity Framework context.</param>
     /// <returns>The Entity Framework context builder.</returns>
-    public static DbModelBuilder UseOpenIddict<TApplication, TAuthorization, TScope, TToken, TKey>(this DbModelBuilder builder)
+    public static DbModelBuilder UseOpenIddict<TApplication, TAuthorization, TScope, TToken, TKey>(this DbModelBuilder builder!!)
         where TApplication : OpenIddictEntityFrameworkApplication<TKey, TAuthorization, TToken>
         where TAuthorization : OpenIddictEntityFrameworkAuthorization<TKey, TApplication, TToken>
         where TScope : OpenIddictEntityFrameworkScope<TKey>
         where TToken : OpenIddictEntityFrameworkToken<TKey, TApplication, TAuthorization>
         where TKey : notnull, IEquatable<TKey>
     {
-        if (builder is null)
-        {
-            throw new ArgumentNullException(nameof(builder));
-        }
-
         builder.Configurations
             .Add(new OpenIddictEntityFrameworkApplicationConfiguration<TApplication, TAuthorization, TToken, TKey>())
             .Add(new OpenIddictEntityFrameworkAuthorizationConfiguration<TAuthorization, TApplication, TToken, TKey>())
@@ -66,13 +61,8 @@ public static class OpenIddictEntityFrameworkHelpers
     /// <param name="source">The query source.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns>The non-streamed async enumeration containing the results.</returns>
-    internal static IAsyncEnumerable<T> AsAsyncEnumerable<T>(this IQueryable<T> source, CancellationToken cancellationToken)
+    internal static IAsyncEnumerable<T> AsAsyncEnumerable<T>(this IQueryable<T> source!!, CancellationToken cancellationToken)
     {
-        if (source is null)
-        {
-            throw new ArgumentNullException(nameof(source));
-        }
-
         return ExecuteAsync(source, cancellationToken);
 
         static async IAsyncEnumerable<T> ExecuteAsync(IQueryable<T> source, [EnumeratorCancellation] CancellationToken cancellationToken)

src/OpenIddict.EntityFramework/Resolvers/OpenIddictEntityFrameworkApplicationStoreResolver.cs

@@ -22,9 +22,9 @@ public class OpenIddictEntityFrameworkApplicationStoreResolver : IOpenIddictAppl
     private readonly IServiceProvider _provider;
 
     public OpenIddictEntityFrameworkApplicationStoreResolver(
-        TypeResolutionCache cache,
-        IOptionsMonitor<OpenIddictEntityFrameworkOptions> options,
-        IServiceProvider provider)
+        TypeResolutionCache cache!!,
+        IOptionsMonitor<OpenIddictEntityFrameworkOptions> options!!,
+        IServiceProvider provider!!)
     {
         _cache = cache;
         _options = options;

src/OpenIddict.EntityFramework/Resolvers/OpenIddictEntityFrameworkAuthorizationStoreResolver.cs

@@ -22,9 +22,9 @@ public class OpenIddictEntityFrameworkAuthorizationStoreResolver : IOpenIddictAu
     private readonly IServiceProvider _provider;
 
     public OpenIddictEntityFrameworkAuthorizationStoreResolver(
-        TypeResolutionCache cache,
-        IOptionsMonitor<OpenIddictEntityFrameworkOptions> options,
-        IServiceProvider provider)
+        TypeResolutionCache cache!!,
+        IOptionsMonitor<OpenIddictEntityFrameworkOptions> options!!,
+        IServiceProvider provider!!)
     {
         _cache = cache;
         _options = options;

src/OpenIddict.EntityFramework/Resolvers/OpenIddictEntityFrameworkScopeStoreResolver.cs

@@ -22,9 +22,9 @@ public class OpenIddictEntityFrameworkScopeStoreResolver : IOpenIddictScopeStore
     private readonly IServiceProvider _provider;
 
     public OpenIddictEntityFrameworkScopeStoreResolver(
-        TypeResolutionCache cache,
-        IOptionsMonitor<OpenIddictEntityFrameworkOptions> options,
-        IServiceProvider provider)
+        TypeResolutionCache cache!!,
+        IOptionsMonitor<OpenIddictEntityFrameworkOptions> options!!,
+        IServiceProvider provider!!)
     {
         _cache = cache;
         _options = options;

src/OpenIddict.EntityFramework/Resolvers/OpenIddictEntityFrameworkTokenStoreResolver.cs

@@ -22,9 +22,9 @@ public class OpenIddictEntityFrameworkTokenStoreResolver : IOpenIddictTokenStore
     private readonly IServiceProvider _provider;
 
     public OpenIddictEntityFrameworkTokenStoreResolver(
-        TypeResolutionCache cache,
-        IOptionsMonitor<OpenIddictEntityFrameworkOptions> options,
-        IServiceProvider provider)
+        TypeResolutionCache cache!!,
+        IOptionsMonitor<OpenIddictEntityFrameworkOptions> options!!,
+        IServiceProvider provider!!)
     {
         _cache = cache;
         _options = options;

src/OpenIddict.EntityFramework/Stores/OpenIddictEntityFrameworkApplicationStore.cs

@@ -32,7 +32,7 @@ public class OpenIddictEntityFrameworkApplicationStore<TContext> :
     public OpenIddictEntityFrameworkApplicationStore(
         IMemoryCache cache,
         TContext context,
-        IOptionsMonitor<OpenIddictEntityFrameworkOptions> options)
+        IOptionsMonitor<OpenIddictEntityFrameworkOptions> options!!)
         : base(cache, context, options)
     {
     }
@@ -54,9 +54,9 @@ public class OpenIddictEntityFrameworkApplicationStore<TApplication, TAuthorizat
     where TKey : notnull, IEquatable<TKey>
 {
     public OpenIddictEntityFrameworkApplicationStore(
-        IMemoryCache cache,
-        TContext context,
-        IOptionsMonitor<OpenIddictEntityFrameworkOptions> options)
+        IMemoryCache cache!!,
+        TContext context!!,
+        IOptionsMonitor<OpenIddictEntityFrameworkOptions> options!!)
     {
         Cache = cache;
         Context = context;
@@ -98,37 +98,20 @@ public class OpenIddictEntityFrameworkApplicationStore<TApplication, TAuthorizat
         => await Applications.LongCountAsync(cancellationToken);
 
     /// <inheritdoc/>
-    public virtual async ValueTask<long> CountAsync<TResult>(Func<IQueryable<TApplication>, IQueryable<TResult>> query, CancellationToken cancellationToken)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return await query(Applications).LongCountAsync(cancellationToken);
-    }
+    public virtual async ValueTask<long> CountAsync<TResult>(Func<IQueryable<TApplication>, IQueryable<TResult>> query!!, CancellationToken cancellationToken)
+        => await query(Applications).LongCountAsync(cancellationToken);
 
     /// <inheritdoc/>
-    public virtual async ValueTask CreateAsync(TApplication application, CancellationToken cancellationToken)
+    public virtual async ValueTask CreateAsync(TApplication application!!, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         Applications.Add(application);
 
         await Context.SaveChangesAsync(cancellationToken);
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask DeleteAsync(TApplication application, CancellationToken cancellationToken)
+    public virtual async ValueTask DeleteAsync(TApplication application!!, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         DbContextTransaction? CreateTransaction()
         {
             try
@@ -303,83 +286,36 @@ public class OpenIddictEntityFrameworkApplicationStore<TApplication, TAuthorizat
 
     /// <inheritdoc/>
     public virtual async ValueTask<TResult?> GetAsync<TState, TResult>(
-        Func<IQueryable<TApplication>, TState, IQueryable<TResult>> query,
+        Func<IQueryable<TApplication>, TState, IQueryable<TResult>> query!!,
         TState state, CancellationToken cancellationToken)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return await query(Applications, state).FirstOrDefaultAsync(cancellationToken);
-    }
+        => await query(Applications, state).FirstOrDefaultAsync(cancellationToken);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetClientIdAsync(TApplication application, CancellationToken cancellationToken)
-    {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        return new ValueTask<string?>(application.ClientId);
-    }
+    public virtual ValueTask<string?> GetClientIdAsync(TApplication application!!, CancellationToken cancellationToken)
+        => new(application.ClientId);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetClientSecretAsync(TApplication application, CancellationToken cancellationToken)
-    {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        return new ValueTask<string?>(application.ClientSecret);
-    }
+    public virtual ValueTask<string?> GetClientSecretAsync(TApplication application!!, CancellationToken cancellationToken)
+        => new(application.ClientSecret);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetClientTypeAsync(TApplication application, CancellationToken cancellationToken)
-    {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        return new ValueTask<string?>(application.Type);
-    }
+    public virtual ValueTask<string?> GetClientTypeAsync(TApplication application!!, CancellationToken cancellationToken)
+        => new(application.Type);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetConsentTypeAsync(TApplication application, CancellationToken cancellationToken)
-    {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        return new ValueTask<string?>(application.ConsentType);
-    }
+    public virtual ValueTask<string?> GetConsentTypeAsync(TApplication application!!, CancellationToken cancellationToken)
+        => new(application.ConsentType);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetDisplayNameAsync(TApplication application, CancellationToken cancellationToken)
-    {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        return new ValueTask<string?>(application.DisplayName);
-    }
+    public virtual ValueTask<string?> GetDisplayNameAsync(TApplication application!!, CancellationToken cancellationToken)
+        => new(application.DisplayName);
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableDictionary<CultureInfo, string>> GetDisplayNamesAsync(TApplication application, CancellationToken cancellationToken)
+    public virtual ValueTask<ImmutableDictionary<CultureInfo, string>> GetDisplayNamesAsync(TApplication application!!, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         if (string.IsNullOrEmpty(application.DisplayNames))
         {
-            return new ValueTask<ImmutableDictionary<CultureInfo, string>>(ImmutableDictionary.Create<CultureInfo, string>());
+            return new(ImmutableDictionary.Create<CultureInfo, string>());
         }
 
         // Note: parsing the stringified display names is an expensive operation.
@@ -407,31 +343,19 @@ public class OpenIddictEntityFrameworkApplicationStore<TApplication, TAuthorizat
             return builder.ToImmutable();
         });
 
-        return new ValueTask<ImmutableDictionary<CultureInfo, string>>(names);
+        return new(names);
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetIdAsync(TApplication application, CancellationToken cancellationToken)
-    {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        return new ValueTask<string?>(ConvertIdentifierToString(application.Id));
-    }
+    public virtual ValueTask<string?> GetIdAsync(TApplication application!!, CancellationToken cancellationToken)
+        => new(ConvertIdentifierToString(application.Id));
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableArray<string>> GetPermissionsAsync(TApplication application, CancellationToken cancellationToken)
+    public virtual ValueTask<ImmutableArray<string>> GetPermissionsAsync(TApplication application!!, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         if (string.IsNullOrEmpty(application.Permissions))
         {
-            return new ValueTask<ImmutableArray<string>>(ImmutableArray.Create<string>());
+            return new(ImmutableArray.Create<string>());
         }
 
         // Note: parsing the stringified permissions is an expensive operation.
@@ -459,20 +383,15 @@ public class OpenIddictEntityFrameworkApplicationStore<TApplication, TAuthorizat
             return builder.ToImmutable();
         });
 
-        return new ValueTask<ImmutableArray<string>>(permissions);
+        return new(permissions);
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableArray<string>> GetPostLogoutRedirectUrisAsync(TApplication application, CancellationToken cancellationToken)
+    public virtual ValueTask<ImmutableArray<string>> GetPostLogoutRedirectUrisAsync(TApplication application!!, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         if (string.IsNullOrEmpty(application.PostLogoutRedirectUris))
         {
-            return new ValueTask<ImmutableArray<string>>(ImmutableArray.Create<string>());
+            return new(ImmutableArray.Create<string>());
         }
 
         // Note: parsing the stringified addresses is an expensive operation.
@@ -500,20 +419,15 @@ public class OpenIddictEntityFrameworkApplicationStore<TApplication, TAuthorizat
             return builder.ToImmutable();
         });
 
-        return new ValueTask<ImmutableArray<string>>(addresses);
+        return new(addresses);
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableDictionary<string, JsonElement>> GetPropertiesAsync(TApplication application, CancellationToken cancellationToken)
+    public virtual ValueTask<ImmutableDictionary<string, JsonElement>> GetPropertiesAsync(TApplication application!!, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         if (string.IsNullOrEmpty(application.Properties))
         {
-            return new ValueTask<ImmutableDictionary<string, JsonElement>>(ImmutableDictionary.Create<string, JsonElement>());
+            return new(ImmutableDictionary.Create<string, JsonElement>());
         }
 
         // Note: parsing the stringified properties is an expensive operation.
@@ -535,20 +449,15 @@ public class OpenIddictEntityFrameworkApplicationStore<TApplication, TAuthorizat
             return builder.ToImmutable();
         });
 
-        return new ValueTask<ImmutableDictionary<string, JsonElement>>(properties);
+        return new(properties);
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableArray<string>> GetRedirectUrisAsync(TApplication application, CancellationToken cancellationToken)
+    public virtual ValueTask<ImmutableArray<string>> GetRedirectUrisAsync(TApplication application!!, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         if (string.IsNullOrEmpty(application.RedirectUris))
         {
-            return new ValueTask<ImmutableArray<string>>(ImmutableArray.Create<string>());
+            return new(ImmutableArray.Create<string>());
         }
 
         // Note: parsing the stringified addresses is an expensive operation.
@@ -576,20 +485,15 @@ public class OpenIddictEntityFrameworkApplicationStore<TApplication, TAuthorizat
             return builder.ToImmutable();
         });
 
-        return new ValueTask<ImmutableArray<string>>(addresses);
+        return new(addresses);
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableArray<string>> GetRequirementsAsync(TApplication application, CancellationToken cancellationToken)
+    public virtual ValueTask<ImmutableArray<string>> GetRequirementsAsync(TApplication application!!, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         if (string.IsNullOrEmpty(application.Requirements))
         {
-            return new ValueTask<ImmutableArray<string>>(ImmutableArray.Create<string>());
+            return new(ImmutableArray.Create<string>());
         }
 
         // Note: parsing the stringified requirements is an expensive operation.
@@ -617,7 +521,7 @@ public class OpenIddictEntityFrameworkApplicationStore<TApplication, TAuthorizat
             return builder.ToImmutable();
         });
 
-        return new ValueTask<ImmutableArray<string>>(requirements);
+        return new(requirements);
     }
 
     /// <inheritdoc/>
@@ -625,12 +529,12 @@ public class OpenIddictEntityFrameworkApplicationStore<TApplication, TAuthorizat
     {
         try
         {
-            return new ValueTask<TApplication>(Activator.CreateInstance<TApplication>());
+            return new(Activator.CreateInstance<TApplication>());
         }
 
         catch (MemberAccessException exception)
         {
-            return new ValueTask<TApplication>(Task.FromException<TApplication>(
+            return new(Task.FromException<TApplication>(
                 new InvalidOperationException(SR.GetResourceString(SR.ID0240), exception)));
         }
     }
@@ -656,91 +560,56 @@ public class OpenIddictEntityFrameworkApplicationStore<TApplication, TAuthorizat
 
     /// <inheritdoc/>
     public virtual IAsyncEnumerable<TResult> ListAsync<TState, TResult>(
-        Func<IQueryable<TApplication>, TState, IQueryable<TResult>> query,
+        Func<IQueryable<TApplication>, TState, IQueryable<TResult>> query!!,
         TState state, CancellationToken cancellationToken)
     {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
         return query(Applications, state).AsAsyncEnumerable(cancellationToken);
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetClientIdAsync(TApplication application, string? identifier, CancellationToken cancellationToken)
+    public virtual ValueTask SetClientIdAsync(TApplication application!!, string? identifier, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         application.ClientId = identifier;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetClientSecretAsync(TApplication application, string? secret, CancellationToken cancellationToken)
+    public virtual ValueTask SetClientSecretAsync(TApplication application!!, string? secret, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         application.ClientSecret = secret;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetClientTypeAsync(TApplication application, string? type, CancellationToken cancellationToken)
+    public virtual ValueTask SetClientTypeAsync(TApplication application!!, string? type, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         application.Type = type;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetConsentTypeAsync(TApplication application, string? type, CancellationToken cancellationToken)
+    public virtual ValueTask SetConsentTypeAsync(TApplication application!!, string? type, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         application.ConsentType = type;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetDisplayNameAsync(TApplication application, string? name, CancellationToken cancellationToken)
+    public virtual ValueTask SetDisplayNameAsync(TApplication application!!, string? name, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         application.DisplayName = name;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetDisplayNamesAsync(TApplication application,
+    public virtual ValueTask SetDisplayNamesAsync(TApplication application!!,
         ImmutableDictionary<CultureInfo, string> names, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         if (names is null || names.IsEmpty)
         {
             application.DisplayNames = null;
@@ -772,13 +641,8 @@ public class OpenIddictEntityFrameworkApplicationStore<TApplication, TAuthorizat
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetPermissionsAsync(TApplication application, ImmutableArray<string> permissions, CancellationToken cancellationToken)
+    public virtual ValueTask SetPermissionsAsync(TApplication application!!, ImmutableArray<string> permissions, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         if (permissions.IsDefaultOrEmpty)
         {
             application.Permissions = null;
@@ -809,14 +673,9 @@ public class OpenIddictEntityFrameworkApplicationStore<TApplication, TAuthorizat
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetPostLogoutRedirectUrisAsync(TApplication application,
+    public virtual ValueTask SetPostLogoutRedirectUrisAsync(TApplication application!!,
         ImmutableArray<string> addresses, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         if (addresses.IsDefaultOrEmpty)
         {
             application.PostLogoutRedirectUris = null;
@@ -847,15 +706,10 @@ public class OpenIddictEntityFrameworkApplicationStore<TApplication, TAuthorizat
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetPropertiesAsync(TApplication application,
+    public virtual ValueTask SetPropertiesAsync(TApplication application!!,
         ImmutableDictionary<string, JsonElement> properties, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        if (properties is null || properties.IsEmpty)
+        if (properties is not { IsEmpty: false })
         {
             application.Properties = null;
 
@@ -886,14 +740,9 @@ public class OpenIddictEntityFrameworkApplicationStore<TApplication, TAuthorizat
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetRedirectUrisAsync(TApplication application,
+    public virtual ValueTask SetRedirectUrisAsync(TApplication application!!,
         ImmutableArray<string> addresses, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         if (addresses.IsDefaultOrEmpty)
         {
             application.RedirectUris = null;
@@ -924,13 +773,8 @@ public class OpenIddictEntityFrameworkApplicationStore<TApplication, TAuthorizat
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetRequirementsAsync(TApplication application, ImmutableArray<string> requirements, CancellationToken cancellationToken)
+    public virtual ValueTask SetRequirementsAsync(TApplication application!!, ImmutableArray<string> requirements, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         if (requirements.IsDefaultOrEmpty)
         {
             application.Requirements = null;
@@ -961,13 +805,8 @@ public class OpenIddictEntityFrameworkApplicationStore<TApplication, TAuthorizat
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask UpdateAsync(TApplication application, CancellationToken cancellationToken)
+    public virtual async ValueTask UpdateAsync(TApplication application!!, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         Applications.Attach(application);
 
         // Generate a new concurrency token and attach it

src/OpenIddict.EntityFramework/Stores/OpenIddictEntityFrameworkAuthorizationStore.cs

@@ -31,7 +31,7 @@ public class OpenIddictEntityFrameworkAuthorizationStore<TContext> :
     public OpenIddictEntityFrameworkAuthorizationStore(
         IMemoryCache cache,
         TContext context,
-        IOptionsMonitor<OpenIddictEntityFrameworkOptions> options)
+        IOptionsMonitor<OpenIddictEntityFrameworkOptions> options!!)
         : base(cache, context, options)
     {
     }
@@ -53,9 +53,9 @@ public class OpenIddictEntityFrameworkAuthorizationStore<TAuthorization, TApplic
     where TKey : notnull, IEquatable<TKey>
 {
     public OpenIddictEntityFrameworkAuthorizationStore(
-        IMemoryCache cache,
-        TContext context,
-        IOptionsMonitor<OpenIddictEntityFrameworkOptions> options)
+        IMemoryCache cache!!,
+        TContext context!!,
+        IOptionsMonitor<OpenIddictEntityFrameworkOptions> options!!)
     {
         Cache = cache;
         Context = context;
@@ -97,37 +97,20 @@ public class OpenIddictEntityFrameworkAuthorizationStore<TAuthorization, TApplic
         => await Authorizations.LongCountAsync(cancellationToken);
 
     /// <inheritdoc/>
-    public virtual async ValueTask<long> CountAsync<TResult>(Func<IQueryable<TAuthorization>, IQueryable<TResult>> query, CancellationToken cancellationToken)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return await query(Authorizations).LongCountAsync(cancellationToken);
-    }
+    public virtual async ValueTask<long> CountAsync<TResult>(Func<IQueryable<TAuthorization>, IQueryable<TResult>> query!!, CancellationToken cancellationToken)
+        => await query(Authorizations).LongCountAsync(cancellationToken);
 
     /// <inheritdoc/>
-    public virtual async ValueTask CreateAsync(TAuthorization authorization, CancellationToken cancellationToken)
+    public virtual async ValueTask CreateAsync(TAuthorization authorization!!, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         Authorizations.Add(authorization);
 
         await Context.SaveChangesAsync(cancellationToken);
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask DeleteAsync(TAuthorization authorization, CancellationToken cancellationToken)
+    public virtual async ValueTask DeleteAsync(TAuthorization authorization!!, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         DbContextTransaction? CreateTransaction()
         {
             try
@@ -361,13 +344,8 @@ public class OpenIddictEntityFrameworkAuthorizationStore<TAuthorization, TApplic
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask<string?> GetApplicationIdAsync(TAuthorization authorization, CancellationToken cancellationToken)
+    public virtual async ValueTask<string?> GetApplicationIdAsync(TAuthorization authorization!!, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         // If the application is not attached to the authorization, try to load it manually.
         if (authorization.Application is null)
         {
@@ -390,56 +368,25 @@ public class OpenIddictEntityFrameworkAuthorizationStore<TAuthorization, TApplic
 
     /// <inheritdoc/>
     public virtual async ValueTask<TResult?> GetAsync<TState, TResult>(
-        Func<IQueryable<TAuthorization>, TState, IQueryable<TResult>> query,
+        Func<IQueryable<TAuthorization>, TState, IQueryable<TResult>> query!!,
         TState state, CancellationToken cancellationToken)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return await query(
+        => await query(
             Authorizations.Include(authorization => authorization.Application), state).FirstOrDefaultAsync(cancellationToken);
-    }
 
     /// <inheritdoc/>
-    public virtual ValueTask<DateTimeOffset?> GetCreationDateAsync(TAuthorization authorization, CancellationToken cancellationToken)
-    {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
-        if (authorization.CreationDate is null)
-        {
-            return new ValueTask<DateTimeOffset?>(result: null);
-        }
-
-        return new ValueTask<DateTimeOffset?>(DateTime.SpecifyKind(authorization.CreationDate.Value, DateTimeKind.Utc));
-    }
+    public virtual ValueTask<DateTimeOffset?> GetCreationDateAsync(TAuthorization authorization!!, CancellationToken cancellationToken)
+        => new(authorization.CreationDate is DateTime date ? DateTime.SpecifyKind(date, DateTimeKind.Utc) : null);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetIdAsync(TAuthorization authorization, CancellationToken cancellationToken)
-    {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
-        return new ValueTask<string?>(ConvertIdentifierToString(authorization.Id));
-    }
+    public virtual ValueTask<string?> GetIdAsync(TAuthorization authorization!!, CancellationToken cancellationToken)
+        => new(ConvertIdentifierToString(authorization.Id));
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableDictionary<string, JsonElement>> GetPropertiesAsync(TAuthorization authorization, CancellationToken cancellationToken)
+    public virtual ValueTask<ImmutableDictionary<string, JsonElement>> GetPropertiesAsync(TAuthorization authorization!!, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         if (string.IsNullOrEmpty(authorization.Properties))
         {
-            return new ValueTask<ImmutableDictionary<string, JsonElement>>(ImmutableDictionary.Create<string, JsonElement>());
+            return new(ImmutableDictionary.Create<string, JsonElement>());
         }
 
         // Note: parsing the stringified properties is an expensive operation.
@@ -461,20 +408,15 @@ public class OpenIddictEntityFrameworkAuthorizationStore<TAuthorization, TApplic
             return builder.ToImmutable();
         });
 
-        return new ValueTask<ImmutableDictionary<string, JsonElement>>(properties);
+        return new(properties);
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableArray<string>> GetScopesAsync(TAuthorization authorization, CancellationToken cancellationToken)
+    public virtual ValueTask<ImmutableArray<string>> GetScopesAsync(TAuthorization authorization!!, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         if (string.IsNullOrEmpty(authorization.Scopes))
         {
-            return new ValueTask<ImmutableArray<string>>(ImmutableArray.Create<string>());
+            return new(ImmutableArray.Create<string>());
         }
 
         // Note: parsing the stringified scopes is an expensive operation.
@@ -502,53 +444,32 @@ public class OpenIddictEntityFrameworkAuthorizationStore<TAuthorization, TApplic
             return builder.ToImmutable();
         });
 
-        return new ValueTask<ImmutableArray<string>>(scopes);
+        return new(scopes);
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetStatusAsync(TAuthorization authorization, CancellationToken cancellationToken)
-    {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
-        return new ValueTask<string?>(authorization.Status);
-    }
+    public virtual ValueTask<string?> GetStatusAsync(TAuthorization authorization!!, CancellationToken cancellationToken)
+        => new(authorization.Status);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetSubjectAsync(TAuthorization authorization, CancellationToken cancellationToken)
-    {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
-        return new ValueTask<string?>(authorization.Subject);
-    }
+    public virtual ValueTask<string?> GetSubjectAsync(TAuthorization authorization!!, CancellationToken cancellationToken)
+        => new(authorization.Subject);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetTypeAsync(TAuthorization authorization, CancellationToken cancellationToken)
-    {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
-        return new ValueTask<string?>(authorization.Type);
-    }
+    public virtual ValueTask<string?> GetTypeAsync(TAuthorization authorization!!, CancellationToken cancellationToken)
+        => new(authorization.Type);
 
     /// <inheritdoc/>
     public virtual ValueTask<TAuthorization> InstantiateAsync(CancellationToken cancellationToken)
     {
         try
         {
-            return new ValueTask<TAuthorization>(Activator.CreateInstance<TAuthorization>());
+            return new(Activator.CreateInstance<TAuthorization>());
         }
 
         catch (MemberAccessException exception)
         {
-            return new ValueTask<TAuthorization>(Task.FromException<TAuthorization>(
+            return new(Task.FromException<TAuthorization>(
                 new InvalidOperationException(SR.GetResourceString(SR.ID0242), exception)));
         }
     }
@@ -575,16 +496,9 @@ public class OpenIddictEntityFrameworkAuthorizationStore<TAuthorization, TApplic
 
     /// <inheritdoc/>
     public virtual IAsyncEnumerable<TResult> ListAsync<TState, TResult>(
-        Func<IQueryable<TAuthorization>, TState, IQueryable<TResult>> query,
+        Func<IQueryable<TAuthorization>, TState, IQueryable<TResult>> query!!,
         TState state, CancellationToken cancellationToken)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return query(Authorizations.Include(authorization => authorization.Application), state).AsAsyncEnumerable(cancellationToken);
-    }
+        => query(Authorizations.Include(authorization => authorization.Application), state).AsAsyncEnumerable(cancellationToken);
 
     /// <inheritdoc/>
     public virtual async ValueTask PruneAsync(DateTimeOffset threshold, CancellationToken cancellationToken)
@@ -668,14 +582,9 @@ public class OpenIddictEntityFrameworkAuthorizationStore<TAuthorization, TApplic
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask SetApplicationIdAsync(TAuthorization authorization,
+    public virtual async ValueTask SetApplicationIdAsync(TAuthorization authorization!!,
         string? identifier, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         if (!string.IsNullOrEmpty(identifier))
         {
             var application = await Applications.FindAsync(cancellationToken, ConvertIdentifierFromString(identifier));
@@ -706,29 +615,19 @@ public class OpenIddictEntityFrameworkAuthorizationStore<TAuthorization, TApplic
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetCreationDateAsync(TAuthorization authorization,
+    public virtual ValueTask SetCreationDateAsync(TAuthorization authorization!!,
         DateTimeOffset? date, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         authorization.CreationDate = date?.UtcDateTime;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetPropertiesAsync(TAuthorization authorization,
+    public virtual ValueTask SetPropertiesAsync(TAuthorization authorization!!,
         ImmutableDictionary<string, JsonElement> properties, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
-        if (properties is null || properties.IsEmpty)
+        if (properties is not { IsEmpty: false })
         {
             authorization.Properties = null;
 
@@ -759,14 +658,9 @@ public class OpenIddictEntityFrameworkAuthorizationStore<TAuthorization, TApplic
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetScopesAsync(TAuthorization authorization,
+    public virtual ValueTask SetScopesAsync(TAuthorization authorization!!,
         ImmutableArray<string> scopes, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         if (scopes.IsDefaultOrEmpty)
         {
             authorization.Scopes = null;
@@ -797,52 +691,32 @@ public class OpenIddictEntityFrameworkAuthorizationStore<TAuthorization, TApplic
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetStatusAsync(TAuthorization authorization, string? status, CancellationToken cancellationToken)
+    public virtual ValueTask SetStatusAsync(TAuthorization authorization!!, string? status, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         authorization.Status = status;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetSubjectAsync(TAuthorization authorization, string? subject, CancellationToken cancellationToken)
+    public virtual ValueTask SetSubjectAsync(TAuthorization authorization!!, string? subject, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         authorization.Subject = subject;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetTypeAsync(TAuthorization authorization, string? type, CancellationToken cancellationToken)
+    public virtual ValueTask SetTypeAsync(TAuthorization authorization!!, string? type, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         authorization.Type = type;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask UpdateAsync(TAuthorization authorization, CancellationToken cancellationToken)
+    public virtual async ValueTask UpdateAsync(TAuthorization authorization!!, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         Authorizations.Attach(authorization);
 
         // Generate a new concurrency token and attach it

src/OpenIddict.EntityFramework/Stores/OpenIddictEntityFrameworkScopeStore.cs

@@ -29,7 +29,7 @@ public class OpenIddictEntityFrameworkScopeStore<TContext> :
     public OpenIddictEntityFrameworkScopeStore(
         IMemoryCache cache,
         TContext context,
-        IOptionsMonitor<OpenIddictEntityFrameworkOptions> options)
+        IOptionsMonitor<OpenIddictEntityFrameworkOptions> options!!)
         : base(cache, context, options)
     {
     }
@@ -47,9 +47,9 @@ public class OpenIddictEntityFrameworkScopeStore<TScope, TContext, TKey> : IOpen
     where TKey : notnull, IEquatable<TKey>
 {
     public OpenIddictEntityFrameworkScopeStore(
-        IMemoryCache cache,
-        TContext context,
-        IOptionsMonitor<OpenIddictEntityFrameworkOptions> options)
+        IMemoryCache cache!!,
+        TContext context!!,
+        IOptionsMonitor<OpenIddictEntityFrameworkOptions> options!!)
     {
         Cache = cache;
         Context = context;
@@ -81,37 +81,20 @@ public class OpenIddictEntityFrameworkScopeStore<TScope, TContext, TKey> : IOpen
         => await Scopes.LongCountAsync(cancellationToken);
 
     /// <inheritdoc/>
-    public virtual async ValueTask<long> CountAsync<TResult>(Func<IQueryable<TScope>, IQueryable<TResult>> query, CancellationToken cancellationToken)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return await query(Scopes).LongCountAsync(cancellationToken);
-    }
+    public virtual async ValueTask<long> CountAsync<TResult>(Func<IQueryable<TScope>, IQueryable<TResult>> query!!, CancellationToken cancellationToken)
+        => await query(Scopes).LongCountAsync(cancellationToken);
 
     /// <inheritdoc/>
-    public virtual async ValueTask CreateAsync(TScope scope, CancellationToken cancellationToken)
+    public virtual async ValueTask CreateAsync(TScope scope!!, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         Scopes.Add(scope);
 
         await Context.SaveChangesAsync(cancellationToken);
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask DeleteAsync(TScope scope, CancellationToken cancellationToken)
+    public virtual async ValueTask DeleteAsync(TScope scope!!, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         Scopes.Remove(scope);
 
         try
@@ -160,7 +143,7 @@ public class OpenIddictEntityFrameworkScopeStore<TScope, TContext, TKey> : IOpen
     public virtual IAsyncEnumerable<TScope> FindByNamesAsync(
         ImmutableArray<string> names, CancellationToken cancellationToken)
     {
-        if (names.Any(name => string.IsNullOrEmpty(name)))
+        if (names.Any(string.IsNullOrEmpty))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0203), nameof(names));
         }
@@ -208,39 +191,20 @@ public class OpenIddictEntityFrameworkScopeStore<TScope, TContext, TKey> : IOpen
 
     /// <inheritdoc/>
     public virtual async ValueTask<TResult?> GetAsync<TState, TResult>(
-        Func<IQueryable<TScope>, TState, IQueryable<TResult>> query,
+        Func<IQueryable<TScope>, TState, IQueryable<TResult>> query!!,
         TState state, CancellationToken cancellationToken)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return await query(Scopes, state).FirstOrDefaultAsync(cancellationToken);
-    }
+        => await query(Scopes, state).FirstOrDefaultAsync(cancellationToken);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetDescriptionAsync(TScope scope, CancellationToken cancellationToken)
-    {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
-        return new ValueTask<string?>(scope.Description);
-    }
+    public virtual ValueTask<string?> GetDescriptionAsync(TScope scope!!, CancellationToken cancellationToken)
+        => new(scope.Description);
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableDictionary<CultureInfo, string>> GetDescriptionsAsync(TScope scope, CancellationToken cancellationToken)
+    public virtual ValueTask<ImmutableDictionary<CultureInfo, string>> GetDescriptionsAsync(TScope scope!!, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         if (string.IsNullOrEmpty(scope.Descriptions))
         {
-            return new ValueTask<ImmutableDictionary<CultureInfo, string>>(ImmutableDictionary.Create<CultureInfo, string>());
+            return new(ImmutableDictionary.Create<CultureInfo, string>());
         }
 
         // Note: parsing the stringified descriptions is an expensive operation.
@@ -268,31 +232,21 @@ public class OpenIddictEntityFrameworkScopeStore<TScope, TContext, TKey> : IOpen
             return builder.ToImmutable();
         });
 
-        return new ValueTask<ImmutableDictionary<CultureInfo, string>>(descriptions);
+        return new(descriptions);
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetDisplayNameAsync(TScope scope, CancellationToken cancellationToken)
+    public virtual ValueTask<string?> GetDisplayNameAsync(TScope scope!!, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
-        return new ValueTask<string?>(scope.DisplayName);
+        return new(scope.DisplayName);
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableDictionary<CultureInfo, string>> GetDisplayNamesAsync(TScope scope, CancellationToken cancellationToken)
+    public virtual ValueTask<ImmutableDictionary<CultureInfo, string>> GetDisplayNamesAsync(TScope scope!!, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         if (string.IsNullOrEmpty(scope.DisplayNames))
         {
-            return new ValueTask<ImmutableDictionary<CultureInfo, string>>(ImmutableDictionary.Create<CultureInfo, string>());
+            return new(ImmutableDictionary.Create<CultureInfo, string>());
         }
 
         // Note: parsing the stringified display names is an expensive operation.
@@ -320,42 +274,23 @@ public class OpenIddictEntityFrameworkScopeStore<TScope, TContext, TKey> : IOpen
             return builder.ToImmutable();
         });
 
-        return new ValueTask<ImmutableDictionary<CultureInfo, string>>(names);
+        return new(names);
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetIdAsync(TScope scope, CancellationToken cancellationToken)
-    {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
-        return new ValueTask<string?>(ConvertIdentifierToString(scope.Id));
-    }
+    public virtual ValueTask<string?> GetIdAsync(TScope scope!!, CancellationToken cancellationToken)
+        => new(ConvertIdentifierToString(scope.Id));
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetNameAsync(TScope scope, CancellationToken cancellationToken)
-    {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
-        return new ValueTask<string?>(scope.Name);
-    }
+    public virtual ValueTask<string?> GetNameAsync(TScope scope!!, CancellationToken cancellationToken)
+        => new(scope.Name);
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableDictionary<string, JsonElement>> GetPropertiesAsync(TScope scope, CancellationToken cancellationToken)
+    public virtual ValueTask<ImmutableDictionary<string, JsonElement>> GetPropertiesAsync(TScope scope!!, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         if (string.IsNullOrEmpty(scope.Properties))
         {
-            return new ValueTask<ImmutableDictionary<string, JsonElement>>(ImmutableDictionary.Create<string, JsonElement>());
+            return new(ImmutableDictionary.Create<string, JsonElement>());
         }
 
         // Note: parsing the stringified properties is an expensive operation.
@@ -377,20 +312,15 @@ public class OpenIddictEntityFrameworkScopeStore<TScope, TContext, TKey> : IOpen
             return builder.ToImmutable();
         });
 
-        return new ValueTask<ImmutableDictionary<string, JsonElement>>(properties);
+        return new(properties);
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableArray<string>> GetResourcesAsync(TScope scope, CancellationToken cancellationToken)
+    public virtual ValueTask<ImmutableArray<string>> GetResourcesAsync(TScope scope!!, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         if (string.IsNullOrEmpty(scope.Resources))
         {
-            return new ValueTask<ImmutableArray<string>>(ImmutableArray.Create<string>());
+            return new(ImmutableArray.Create<string>());
         }
 
         // Note: parsing the stringified resources is an expensive operation.
@@ -418,7 +348,7 @@ public class OpenIddictEntityFrameworkScopeStore<TScope, TContext, TKey> : IOpen
             return builder.ToImmutable();
         });
 
-        return new ValueTask<ImmutableArray<string>>(resources);
+        return new(resources);
     }
 
     /// <inheritdoc/>
@@ -426,12 +356,12 @@ public class OpenIddictEntityFrameworkScopeStore<TScope, TContext, TKey> : IOpen
     {
         try
         {
-            return new ValueTask<TScope>(Activator.CreateInstance<TScope>());
+            return new(Activator.CreateInstance<TScope>());
         }
 
         catch (MemberAccessException exception)
         {
-            return new ValueTask<TScope>(Task.FromException<TScope>(
+            return new(Task.FromException<TScope>(
                 new InvalidOperationException(SR.GetResourceString(SR.ID0246), exception)));
         }
     }
@@ -456,39 +386,22 @@ public class OpenIddictEntityFrameworkScopeStore<TScope, TContext, TKey> : IOpen
 
     /// <inheritdoc/>
     public virtual IAsyncEnumerable<TResult> ListAsync<TState, TResult>(
-        Func<IQueryable<TScope>, TState, IQueryable<TResult>> query,
+        Func<IQueryable<TScope>, TState, IQueryable<TResult>> query!!,
         TState state, CancellationToken cancellationToken)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return query(Scopes, state).AsAsyncEnumerable(cancellationToken);
-    }
+        => query(Scopes, state).AsAsyncEnumerable(cancellationToken);
 
     /// <inheritdoc/>
-    public virtual ValueTask SetDescriptionAsync(TScope scope, string? description, CancellationToken cancellationToken)
+    public virtual ValueTask SetDescriptionAsync(TScope scope!!, string? description, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         scope.Description = description;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetDescriptionsAsync(TScope scope,
+    public virtual ValueTask SetDescriptionsAsync(TScope scope!!,
         ImmutableDictionary<CultureInfo, string> descriptions, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         if (descriptions is null || descriptions.IsEmpty)
         {
             scope.Descriptions = null;
@@ -520,27 +433,17 @@ public class OpenIddictEntityFrameworkScopeStore<TScope, TContext, TKey> : IOpen
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetDisplayNameAsync(TScope scope, string? name, CancellationToken cancellationToken)
+    public virtual ValueTask SetDisplayNameAsync(TScope scope!!, string? name, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         scope.DisplayName = name;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetDisplayNamesAsync(TScope scope,
+    public virtual ValueTask SetDisplayNamesAsync(TScope scope!!,
         ImmutableDictionary<CultureInfo, string> names, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         if (names is null || names.IsEmpty)
         {
             scope.DisplayNames = null;
@@ -572,28 +475,18 @@ public class OpenIddictEntityFrameworkScopeStore<TScope, TContext, TKey> : IOpen
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetNameAsync(TScope scope, string? name, CancellationToken cancellationToken)
+    public virtual ValueTask SetNameAsync(TScope scope!!, string? name, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         scope.Name = name;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetPropertiesAsync(TScope scope,
+    public virtual ValueTask SetPropertiesAsync(TScope scope!!,
         ImmutableDictionary<string, JsonElement> properties, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
-        if (properties is null || properties.IsEmpty)
+        if (properties is not { IsEmpty: false })
         {
             scope.Properties = null;
 
@@ -624,13 +517,8 @@ public class OpenIddictEntityFrameworkScopeStore<TScope, TContext, TKey> : IOpen
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetResourcesAsync(TScope scope, ImmutableArray<string> resources, CancellationToken cancellationToken)
+    public virtual ValueTask SetResourcesAsync(TScope scope!!, ImmutableArray<string> resources, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         if (resources.IsDefaultOrEmpty)
         {
             scope.Resources = null;
@@ -661,13 +549,8 @@ public class OpenIddictEntityFrameworkScopeStore<TScope, TContext, TKey> : IOpen
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask UpdateAsync(TScope scope, CancellationToken cancellationToken)
+    public virtual async ValueTask UpdateAsync(TScope scope!!, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         Scopes.Attach(scope);
 
         // Generate a new concurrency token and attach it

src/OpenIddict.EntityFramework/Stores/OpenIddictEntityFrameworkTokenStore.cs

@@ -30,7 +30,7 @@ public class OpenIddictEntityFrameworkTokenStore<TContext> :
     public OpenIddictEntityFrameworkTokenStore(
         IMemoryCache cache,
         TContext context,
-        IOptionsMonitor<OpenIddictEntityFrameworkOptions> options)
+        IOptionsMonitor<OpenIddictEntityFrameworkOptions> options!!)
         : base(cache, context, options)
     {
     }
@@ -52,9 +52,9 @@ public class OpenIddictEntityFrameworkTokenStore<TToken, TApplication, TAuthoriz
     where TKey : notnull, IEquatable<TKey>
 {
     public OpenIddictEntityFrameworkTokenStore(
-        IMemoryCache cache,
-        TContext context,
-        IOptionsMonitor<OpenIddictEntityFrameworkOptions> options)
+        IMemoryCache cache!!,
+        TContext context!!,
+        IOptionsMonitor<OpenIddictEntityFrameworkOptions> options!!)
     {
         Cache = cache;
         Context = context;
@@ -96,37 +96,20 @@ public class OpenIddictEntityFrameworkTokenStore<TToken, TApplication, TAuthoriz
         => await Tokens.LongCountAsync(cancellationToken);
 
     /// <inheritdoc/>
-    public virtual async ValueTask<long> CountAsync<TResult>(Func<IQueryable<TToken>, IQueryable<TResult>> query, CancellationToken cancellationToken)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return await query(Tokens).LongCountAsync(cancellationToken);
-    }
+    public virtual async ValueTask<long> CountAsync<TResult>(Func<IQueryable<TToken>, IQueryable<TResult>> query!!, CancellationToken cancellationToken)
+        => await query(Tokens).LongCountAsync(cancellationToken);
 
     /// <inheritdoc/>
-    public virtual async ValueTask CreateAsync(TToken token, CancellationToken cancellationToken)
+    public virtual async ValueTask CreateAsync(TToken token!!, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         Tokens.Add(token);
 
         await Context.SaveChangesAsync(cancellationToken);
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask DeleteAsync(TToken token, CancellationToken cancellationToken)
+    public virtual async ValueTask DeleteAsync(TToken token!!, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         Tokens.Remove(token);
 
         try
@@ -301,13 +284,8 @@ public class OpenIddictEntityFrameworkTokenStore<TToken, TApplication, TAuthoriz
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask<string?> GetApplicationIdAsync(TToken token, CancellationToken cancellationToken)
+    public virtual async ValueTask<string?> GetApplicationIdAsync(TToken token!!, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         // If the application is not attached to the token, try to load it manually.
         if (token.Application is null)
         {
@@ -330,27 +308,15 @@ public class OpenIddictEntityFrameworkTokenStore<TToken, TApplication, TAuthoriz
 
     /// <inheritdoc/>
     public virtual async ValueTask<TResult?> GetAsync<TState, TResult>(
-        Func<IQueryable<TToken>, TState, IQueryable<TResult>> query,
+        Func<IQueryable<TToken>, TState, IQueryable<TResult>> query!!,
         TState state, CancellationToken cancellationToken)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return await query(
+        => await query(
             Tokens.Include(token => token.Application)
                   .Include(token => token.Authorization), state).FirstOrDefaultAsync(cancellationToken);
-    }
 
     /// <inheritdoc/>
-    public virtual async ValueTask<string?> GetAuthorizationIdAsync(TToken token, CancellationToken cancellationToken)
+    public virtual async ValueTask<string?> GetAuthorizationIdAsync(TToken token!!, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         // If the authorization is not attached to the token, try to load it manually.
         if (token.Authorization is null)
         {
@@ -372,70 +338,27 @@ public class OpenIddictEntityFrameworkTokenStore<TToken, TApplication, TAuthoriz
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<DateTimeOffset?> GetCreationDateAsync(TToken token, CancellationToken cancellationToken)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        if (token.CreationDate is null)
-        {
-            return new ValueTask<DateTimeOffset?>(result: null);
-        }
-
-        return new ValueTask<DateTimeOffset?>(DateTime.SpecifyKind(token.CreationDate.Value, DateTimeKind.Utc));
-    }
+    public virtual ValueTask<DateTimeOffset?> GetCreationDateAsync(TToken token!!, CancellationToken cancellationToken)
+        => new(token.CreationDate is DateTime date ? DateTime.SpecifyKind(date, DateTimeKind.Utc) : null);
 
     /// <inheritdoc/>
-    public virtual ValueTask<DateTimeOffset?> GetExpirationDateAsync(TToken token, CancellationToken cancellationToken)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        if (token.ExpirationDate is null)
-        {
-            return new ValueTask<DateTimeOffset?>(result: null);
-        }
-
-        return new ValueTask<DateTimeOffset?>(DateTime.SpecifyKind(token.ExpirationDate.Value, DateTimeKind.Utc));
-    }
+    public virtual ValueTask<DateTimeOffset?> GetExpirationDateAsync(TToken token!!, CancellationToken cancellationToken)
+        => new(token.ExpirationDate is DateTime date ? DateTime.SpecifyKind(date, DateTimeKind.Utc) : null);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetIdAsync(TToken token, CancellationToken cancellationToken)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        return new ValueTask<string?>(ConvertIdentifierToString(token.Id));
-    }
+    public virtual ValueTask<string?> GetIdAsync(TToken token!!, CancellationToken cancellationToken)
+        => new(ConvertIdentifierToString(token.Id));
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetPayloadAsync(TToken token, CancellationToken cancellationToken)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        return new ValueTask<string?>(token.Payload);
-    }
+    public virtual ValueTask<string?> GetPayloadAsync(TToken token!!, CancellationToken cancellationToken)
+        => new(token.Payload);
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableDictionary<string, JsonElement>> GetPropertiesAsync(TToken token, CancellationToken cancellationToken)
+    public virtual ValueTask<ImmutableDictionary<string, JsonElement>> GetPropertiesAsync(TToken token!!, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         if (string.IsNullOrEmpty(token.Properties))
         {
-            return new ValueTask<ImmutableDictionary<string, JsonElement>>(ImmutableDictionary.Create<string, JsonElement>());
+            return new(ImmutableDictionary.Create<string, JsonElement>());
         }
 
         // Note: parsing the stringified properties is an expensive operation.
@@ -457,80 +380,40 @@ public class OpenIddictEntityFrameworkTokenStore<TToken, TApplication, TAuthoriz
             return builder.ToImmutable();
         });
 
-        return new ValueTask<ImmutableDictionary<string, JsonElement>>(properties);
+        return new(properties);
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<DateTimeOffset?> GetRedemptionDateAsync(TToken token, CancellationToken cancellationToken)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        if (token.RedemptionDate is null)
-        {
-            return new ValueTask<DateTimeOffset?>(result: null);
-        }
-
-        return new ValueTask<DateTimeOffset?>(DateTime.SpecifyKind(token.RedemptionDate.Value, DateTimeKind.Utc));
-    }
+    public virtual ValueTask<DateTimeOffset?> GetRedemptionDateAsync(TToken token!!, CancellationToken cancellationToken)
+        => new(token.RedemptionDate is DateTime date ? DateTime.SpecifyKind(date, DateTimeKind.Utc) : null);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetReferenceIdAsync(TToken token, CancellationToken cancellationToken)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        return new ValueTask<string?>(token.ReferenceId);
-    }
+    public virtual ValueTask<string?> GetReferenceIdAsync(TToken token!!, CancellationToken cancellationToken)
+        => new(token.ReferenceId);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetStatusAsync(TToken token, CancellationToken cancellationToken)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        return new ValueTask<string?>(token.Status);
-    }
+    public virtual ValueTask<string?> GetStatusAsync(TToken token!!, CancellationToken cancellationToken)
+        => new(token.Status);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetSubjectAsync(TToken token, CancellationToken cancellationToken)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        return new ValueTask<string?>(token.Subject);
-    }
+    public virtual ValueTask<string?> GetSubjectAsync(TToken token!!, CancellationToken cancellationToken)
+        => new(token.Subject);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetTypeAsync(TToken token, CancellationToken cancellationToken)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        return new ValueTask<string?>(token.Type);
-    }
+    public virtual ValueTask<string?> GetTypeAsync(TToken token!!, CancellationToken cancellationToken)
+        => new(token.Type);
 
     /// <inheritdoc/>
     public virtual ValueTask<TToken> InstantiateAsync(CancellationToken cancellationToken)
     {
         try
         {
-            return new ValueTask<TToken>(Activator.CreateInstance<TToken>());
+            return new(Activator.CreateInstance<TToken>());
         }
 
         catch (MemberAccessException exception)
         {
-            return new ValueTask<TToken>(Task.FromException<TToken>(
+            return new(Task.FromException<TToken>(
                 new InvalidOperationException(SR.GetResourceString(SR.ID0248), exception)));
         }
     }
@@ -558,18 +441,11 @@ public class OpenIddictEntityFrameworkTokenStore<TToken, TApplication, TAuthoriz
 
     /// <inheritdoc/>
     public virtual IAsyncEnumerable<TResult> ListAsync<TState, TResult>(
-        Func<IQueryable<TToken>, TState, IQueryable<TResult>> query,
+        Func<IQueryable<TToken>, TState, IQueryable<TResult>> query!!,
         TState state, CancellationToken cancellationToken)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return query(
+        => query(
             Tokens.Include(token => token.Application)
                   .Include(token => token.Authorization), state).AsAsyncEnumerable(cancellationToken);
-    }
 
     /// <inheritdoc/>
     public virtual async ValueTask PruneAsync(DateTimeOffset threshold, CancellationToken cancellationToken)
@@ -650,13 +526,8 @@ public class OpenIddictEntityFrameworkTokenStore<TToken, TApplication, TAuthoriz
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask SetApplicationIdAsync(TToken token, string? identifier, CancellationToken cancellationToken)
+    public virtual async ValueTask SetApplicationIdAsync(TToken token!!, string? identifier, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         if (!string.IsNullOrEmpty(identifier))
         {
             var application = await Applications.FindAsync(cancellationToken, ConvertIdentifierFromString(identifier));
@@ -687,13 +558,8 @@ public class OpenIddictEntityFrameworkTokenStore<TToken, TApplication, TAuthoriz
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask SetAuthorizationIdAsync(TToken token, string? identifier, CancellationToken cancellationToken)
+    public virtual async ValueTask SetAuthorizationIdAsync(TToken token!!, string? identifier, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         if (!string.IsNullOrEmpty(identifier))
         {
             var authorization = await Authorizations.FindAsync(cancellationToken, ConvertIdentifierFromString(identifier));
@@ -724,54 +590,34 @@ public class OpenIddictEntityFrameworkTokenStore<TToken, TApplication, TAuthoriz
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetCreationDateAsync(TToken token, DateTimeOffset? date, CancellationToken cancellationToken)
+    public virtual ValueTask SetCreationDateAsync(TToken token!!, DateTimeOffset? date, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         token.CreationDate = date?.UtcDateTime;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetExpirationDateAsync(TToken token, DateTimeOffset? date, CancellationToken cancellationToken)
+    public virtual ValueTask SetExpirationDateAsync(TToken token!!, DateTimeOffset? date, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         token.ExpirationDate = date?.UtcDateTime;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetPayloadAsync(TToken token, string? payload, CancellationToken cancellationToken)
+    public virtual ValueTask SetPayloadAsync(TToken token!!, string? payload, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         token.Payload = payload;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetPropertiesAsync(TToken token,
+    public virtual ValueTask SetPropertiesAsync(TToken token!!,
         ImmutableDictionary<string, JsonElement> properties, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        if (properties is null || properties.IsEmpty)
+        if (properties is not { IsEmpty: false })
         {
             token.Properties = null;
 
@@ -802,78 +648,48 @@ public class OpenIddictEntityFrameworkTokenStore<TToken, TApplication, TAuthoriz
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetRedemptionDateAsync(TToken token, DateTimeOffset? date, CancellationToken cancellationToken)
+    public virtual ValueTask SetRedemptionDateAsync(TToken token!!, DateTimeOffset? date, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         token.RedemptionDate = date?.UtcDateTime;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetReferenceIdAsync(TToken token, string? identifier, CancellationToken cancellationToken)
+    public virtual ValueTask SetReferenceIdAsync(TToken token!!, string? identifier, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         token.ReferenceId = identifier;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetStatusAsync(TToken token, string? status, CancellationToken cancellationToken)
+    public virtual ValueTask SetStatusAsync(TToken token!!, string? status, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         token.Status = status;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetSubjectAsync(TToken token, string? subject, CancellationToken cancellationToken)
+    public virtual ValueTask SetSubjectAsync(TToken token!!, string? subject, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         token.Subject = subject;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetTypeAsync(TToken token, string? type, CancellationToken cancellationToken)
+    public virtual ValueTask SetTypeAsync(TToken token!!, string? type, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         token.Type = type;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask UpdateAsync(TToken token, CancellationToken cancellationToken)
+    public virtual async ValueTask UpdateAsync(TToken token!!, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         Tokens.Attach(token);
 
         // Generate a new concurrency token and attach it

src/OpenIddict.EntityFrameworkCore/Configurations/OpenIddictEntityFrameworkCoreApplicationConfiguration.cs

@@ -24,13 +24,8 @@ public class OpenIddictEntityFrameworkCoreApplicationConfiguration<TApplication,
     where TToken : OpenIddictEntityFrameworkCoreToken<TKey, TApplication, TAuthorization>
     where TKey : notnull, IEquatable<TKey>
 {
-    public void Configure(EntityTypeBuilder<TApplication> builder)
+    public void Configure(EntityTypeBuilder<TApplication> builder!!)
     {
-        if (builder is null)
-        {
-            throw new ArgumentNullException(nameof(builder));
-        }
-
         // Warning: optional foreign keys MUST NOT be added as CLR properties because
         // Entity Framework would throw an exception due to the TKey generic parameter
         // being non-nullable when using value types like short, int, long or Guid.

src/OpenIddict.EntityFrameworkCore/Configurations/OpenIddictEntityFrameworkCoreAuthorizationConfiguration.cs

@@ -24,13 +24,8 @@ public class OpenIddictEntityFrameworkCoreAuthorizationConfiguration<TAuthorizat
     where TToken : OpenIddictEntityFrameworkCoreToken<TKey, TApplication, TAuthorization>
     where TKey : notnull, IEquatable<TKey>
 {
-    public void Configure(EntityTypeBuilder<TAuthorization> builder)
+    public void Configure(EntityTypeBuilder<TAuthorization> builder!!)
     {
-        if (builder is null)
-        {
-            throw new ArgumentNullException(nameof(builder));
-        }
-
         // Warning: optional foreign keys MUST NOT be added as CLR properties because
         // Entity Framework would throw an exception due to the TKey generic parameter
         // being non-nullable when using value types like short, int, long or Guid.

src/OpenIddict.EntityFrameworkCore/Configurations/OpenIddictEntityFrameworkCoreScopeConfiguration.cs

@@ -20,13 +20,8 @@ public class OpenIddictEntityFrameworkCoreScopeConfiguration<TScope, TKey> : IEn
     where TScope : OpenIddictEntityFrameworkCoreScope<TKey>
     where TKey : notnull, IEquatable<TKey>
 {
-    public void Configure(EntityTypeBuilder<TScope> builder)
+    public void Configure(EntityTypeBuilder<TScope> builder!!)
     {
-        if (builder is null)
-        {
-            throw new ArgumentNullException(nameof(builder));
-        }
-
         // Warning: optional foreign keys MUST NOT be added as CLR properties because
         // Entity Framework would throw an exception due to the TKey generic parameter
         // being non-nullable when using value types like short, int, long or Guid.

src/OpenIddict.EntityFrameworkCore/Configurations/OpenIddictEntityFrameworkCoreTokenConfiguration.cs

@@ -24,13 +24,8 @@ public class OpenIddictEntityFrameworkCoreTokenConfiguration<TToken, TApplicatio
     where TAuthorization : OpenIddictEntityFrameworkCoreAuthorization<TKey, TApplication, TToken>
     where TKey : notnull, IEquatable<TKey>
 {
-    public void Configure(EntityTypeBuilder<TToken> builder)
+    public void Configure(EntityTypeBuilder<TToken> builder!!)
     {
-        if (builder is null)
-        {
-            throw new ArgumentNullException(nameof(builder));
-        }
-
         // Warning: optional foreign keys MUST NOT be added as CLR properties because
         // Entity Framework would throw an exception due to the TKey generic parameter
         // being non-nullable when using value types like short, int, long or Guid.

src/OpenIddict.EntityFrameworkCore/OpenIddictEntityFrameworkCoreBuilder.cs

@@ -20,8 +20,8 @@ public class OpenIddictEntityFrameworkCoreBuilder
     /// Initializes a new instance of <see cref="OpenIddictEntityFrameworkCoreBuilder"/>.
     /// </summary>
     /// <param name="services">The services collection.</param>
-    public OpenIddictEntityFrameworkCoreBuilder(IServiceCollection services)
-        => Services = services ?? throw new ArgumentNullException(nameof(services));
+    public OpenIddictEntityFrameworkCoreBuilder(IServiceCollection services!!)
+        => Services = services;
 
     /// <summary>
     /// Gets the services collection.
@@ -35,13 +35,8 @@ public class OpenIddictEntityFrameworkCoreBuilder
     /// <param name="configuration">The delegate used to configure the OpenIddict options.</param>
     /// <remarks>This extension can be safely called multiple times.</remarks>
     /// <returns>The <see cref="OpenIddictEntityFrameworkCoreBuilder"/>.</returns>
-    public OpenIddictEntityFrameworkCoreBuilder Configure(Action<OpenIddictEntityFrameworkCoreOptions> configuration)
+    public OpenIddictEntityFrameworkCoreBuilder Configure(Action<OpenIddictEntityFrameworkCoreOptions> configuration!!)
     {
-        if (configuration is null)
-        {
-            throw new ArgumentNullException(nameof(configuration));
-        }
-
         Services.Configure(configuration);
 
         return this;
@@ -96,13 +91,8 @@ public class OpenIddictEntityFrameworkCoreBuilder
     /// </summary>
     /// <param name="type">The type of the <see cref="DbContext"/> used by OpenIddict.</param>
     /// <returns>The <see cref="OpenIddictEntityFrameworkCoreBuilder"/>.</returns>
-    public OpenIddictEntityFrameworkCoreBuilder UseDbContext(Type type)
+    public OpenIddictEntityFrameworkCoreBuilder UseDbContext(Type type!!)
     {
-        if (type is null)
-        {
-            throw new ArgumentNullException(nameof(type));
-        }
-
         if (!typeof(DbContext).IsAssignableFrom(type))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0232), nameof(type));

src/OpenIddict.EntityFrameworkCore/OpenIddictEntityFrameworkCoreCustomizer.cs

@@ -25,18 +25,8 @@ public class OpenIddictEntityFrameworkCoreCustomizer<TApplication, TAuthorizatio
     }
 
     /// <inheritdoc/>
-    public override void Customize(ModelBuilder modelBuilder, DbContext context)
+    public override void Customize(ModelBuilder modelBuilder!!, DbContext context!!)
     {
-        if (modelBuilder is null)
-        {
-            throw new ArgumentNullException(nameof(modelBuilder));
-        }
-
-        if (context is null)
-        {
-            throw new ArgumentNullException(nameof(context));
-        }
-
         // Register the OpenIddict entity sets.
         modelBuilder.UseOpenIddict<TApplication, TAuthorization, TScope, TToken, TKey>();
 

src/OpenIddict.EntityFrameworkCore/OpenIddictEntityFrameworkCoreExtensions.cs

@@ -22,13 +22,8 @@ public static class OpenIddictEntityFrameworkCoreExtensions
     /// <param name="builder">The services builder used by OpenIddict to register new services.</param>
     /// <remarks>This extension can be safely called multiple times.</remarks>
     /// <returns>The <see cref="OpenIddictEntityFrameworkCoreBuilder"/>.</returns>
-    public static OpenIddictEntityFrameworkCoreBuilder UseEntityFrameworkCore(this OpenIddictCoreBuilder builder)
+    public static OpenIddictEntityFrameworkCoreBuilder UseEntityFrameworkCore(this OpenIddictCoreBuilder builder!!)
     {
-        if (builder is null)
-        {
-            throw new ArgumentNullException(nameof(builder));
-        }
-
         // Since Entity Framework Core may be used with databases performing case-insensitive
         // or culture-sensitive comparisons, ensure the additional filtering logic is enforced
         // in case case-sensitive stores were registered before this extension was called.
@@ -66,18 +61,8 @@ public static class OpenIddictEntityFrameworkCoreExtensions
     /// <remarks>This extension can be safely called multiple times.</remarks>
     /// <returns>The <see cref="OpenIddictCoreBuilder"/>.</returns>
     public static OpenIddictCoreBuilder UseEntityFrameworkCore(
-        this OpenIddictCoreBuilder builder, Action<OpenIddictEntityFrameworkCoreBuilder> configuration)
+        this OpenIddictCoreBuilder builder!!, Action<OpenIddictEntityFrameworkCoreBuilder> configuration!!)
     {
-        if (builder is null)
-        {
-            throw new ArgumentNullException(nameof(builder));
-        }
-
-        if (configuration is null)
-        {
-            throw new ArgumentNullException(nameof(configuration));
-        }
-
         configuration(builder.UseEntityFrameworkCore());
 
         return builder;

src/OpenIddict.EntityFrameworkCore/OpenIddictEntityFrameworkCoreHelpers.cs

@@ -56,21 +56,14 @@ public static class OpenIddictEntityFrameworkCoreHelpers
     /// <param name="builder">The builder used to configure the Entity Framework context.</param>
     /// <returns>The Entity Framework context builder.</returns>
     public static DbContextOptionsBuilder UseOpenIddict<TApplication, TAuthorization, TScope, TToken, TKey>(
-        this DbContextOptionsBuilder builder)
+        this DbContextOptionsBuilder builder!!)
         where TApplication : OpenIddictEntityFrameworkCoreApplication<TKey, TAuthorization, TToken>
         where TAuthorization : OpenIddictEntityFrameworkCoreAuthorization<TKey, TApplication, TToken>
         where TScope : OpenIddictEntityFrameworkCoreScope<TKey>
         where TToken : OpenIddictEntityFrameworkCoreToken<TKey, TApplication, TAuthorization>
         where TKey : notnull, IEquatable<TKey>
-    {
-        if (builder is null)
-        {
-            throw new ArgumentNullException(nameof(builder));
-        }
-
-        return builder.ReplaceService<IModelCustomizer, OpenIddictEntityFrameworkCoreCustomizer<
+        => builder.ReplaceService<IModelCustomizer, OpenIddictEntityFrameworkCoreCustomizer<
             TApplication, TAuthorization, TScope, TToken, TKey>>();
-    }
 
     /// <summary>
     /// Registers the OpenIddict entity sets in the Entity Framework Core context
@@ -110,24 +103,17 @@ public static class OpenIddictEntityFrameworkCoreHelpers
     /// </remarks>
     /// <param name="builder">The builder used to configure the Entity Framework context.</param>
     /// <returns>The Entity Framework context builder.</returns>
-    public static ModelBuilder UseOpenIddict<TApplication, TAuthorization, TScope, TToken, TKey>(this ModelBuilder builder)
+    public static ModelBuilder UseOpenIddict<TApplication, TAuthorization, TScope, TToken, TKey>(this ModelBuilder builder!!)
         where TApplication : OpenIddictEntityFrameworkCoreApplication<TKey, TAuthorization, TToken>
         where TAuthorization : OpenIddictEntityFrameworkCoreAuthorization<TKey, TApplication, TToken>
         where TScope : OpenIddictEntityFrameworkCoreScope<TKey>
         where TToken : OpenIddictEntityFrameworkCoreToken<TKey, TApplication, TAuthorization>
         where TKey : notnull, IEquatable<TKey>
-    {
-        if (builder is null)
-        {
-            throw new ArgumentNullException(nameof(builder));
-        }
-
-        return builder
+        => builder
             .ApplyConfiguration(new OpenIddictEntityFrameworkCoreApplicationConfiguration<TApplication, TAuthorization, TToken, TKey>())
             .ApplyConfiguration(new OpenIddictEntityFrameworkCoreAuthorizationConfiguration<TAuthorization, TApplication, TToken, TKey>())
             .ApplyConfiguration(new OpenIddictEntityFrameworkCoreScopeConfiguration<TScope, TKey>())
             .ApplyConfiguration(new OpenIddictEntityFrameworkCoreTokenConfiguration<TToken, TApplication, TAuthorization, TKey>());
-    }
 
 #if SUPPORTS_BCL_ASYNC_ENUMERABLE
     /// <summary>
@@ -146,13 +132,8 @@ public static class OpenIddictEntityFrameworkCoreHelpers
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns>The non-streamed async enumeration containing the results.</returns>
 #endif
-    internal static IAsyncEnumerable<T> AsAsyncEnumerable<T>(this IQueryable<T> source, CancellationToken cancellationToken)
+    internal static IAsyncEnumerable<T> AsAsyncEnumerable<T>(this IQueryable<T> source!!, CancellationToken cancellationToken)
     {
-        if (source is null)
-        {
-            throw new ArgumentNullException(nameof(source));
-        }
-
         return ExecuteAsync(source, cancellationToken);
 
         static async IAsyncEnumerable<T> ExecuteAsync(IQueryable<T> source, [EnumeratorCancellation] CancellationToken cancellationToken)

src/OpenIddict.EntityFrameworkCore/Resolvers/OpenIddictEntityFrameworkCoreApplicationStoreResolver.cs

@@ -22,9 +22,9 @@ public class OpenIddictEntityFrameworkCoreApplicationStoreResolver : IOpenIddict
     private readonly IServiceProvider _provider;
 
     public OpenIddictEntityFrameworkCoreApplicationStoreResolver(
-        TypeResolutionCache cache,
-        IOptionsMonitor<OpenIddictEntityFrameworkCoreOptions> options,
-        IServiceProvider provider)
+        TypeResolutionCache cache!!,
+        IOptionsMonitor<OpenIddictEntityFrameworkCoreOptions> options!!,
+        IServiceProvider provider!!)
     {
         _cache = cache;
         _options = options;

src/OpenIddict.EntityFrameworkCore/Resolvers/OpenIddictEntityFrameworkCoreAuthorizationStoreResolver.cs

@@ -22,9 +22,9 @@ public class OpenIddictEntityFrameworkCoreAuthorizationStoreResolver : IOpenIddi
     private readonly IServiceProvider _provider;
 
     public OpenIddictEntityFrameworkCoreAuthorizationStoreResolver(
-        TypeResolutionCache cache,
-        IOptionsMonitor<OpenIddictEntityFrameworkCoreOptions> options,
-        IServiceProvider provider)
+        TypeResolutionCache cache!!,
+        IOptionsMonitor<OpenIddictEntityFrameworkCoreOptions> options!!,
+        IServiceProvider provider!!)
     {
         _cache = cache;
         _options = options;

src/OpenIddict.EntityFrameworkCore/Resolvers/OpenIddictEntityFrameworkCoreScopeStoreResolver.cs

@@ -22,9 +22,9 @@ public class OpenIddictEntityFrameworkCoreScopeStoreResolver : IOpenIddictScopeS
     private readonly IServiceProvider _provider;
 
     public OpenIddictEntityFrameworkCoreScopeStoreResolver(
-        TypeResolutionCache cache,
-        IOptionsMonitor<OpenIddictEntityFrameworkCoreOptions> options,
-        IServiceProvider provider)
+        TypeResolutionCache cache!!,
+        IOptionsMonitor<OpenIddictEntityFrameworkCoreOptions> options!!,
+        IServiceProvider provider!!)
     {
         _cache = cache;
         _options = options;

src/OpenIddict.EntityFrameworkCore/Resolvers/OpenIddictEntityFrameworkCoreTokenStoreResolver.cs

@@ -22,9 +22,9 @@ public class OpenIddictEntityFrameworkCoreTokenStoreResolver : IOpenIddictTokenS
     private readonly IServiceProvider _provider;
 
     public OpenIddictEntityFrameworkCoreTokenStoreResolver(
-        TypeResolutionCache cache,
-        IOptionsMonitor<OpenIddictEntityFrameworkCoreOptions> options,
-        IServiceProvider provider)
+        TypeResolutionCache cache!!,
+        IOptionsMonitor<OpenIddictEntityFrameworkCoreOptions> options!!,
+        IServiceProvider provider!!)
     {
         _cache = cache;
         _options = options;

src/OpenIddict.EntityFrameworkCore/Stores/OpenIddictEntityFrameworkCoreApplicationStore.cs

@@ -31,7 +31,7 @@ public class OpenIddictEntityFrameworkCoreApplicationStore<TContext> :
     public OpenIddictEntityFrameworkCoreApplicationStore(
         IMemoryCache cache,
         TContext context,
-        IOptionsMonitor<OpenIddictEntityFrameworkCoreOptions> options)
+        IOptionsMonitor<OpenIddictEntityFrameworkCoreOptions> options!!)
         : base(cache, context, options)
     {
     }
@@ -52,7 +52,7 @@ public class OpenIddictEntityFrameworkCoreApplicationStore<TContext, TKey> :
     public OpenIddictEntityFrameworkCoreApplicationStore(
         IMemoryCache cache,
         TContext context,
-        IOptionsMonitor<OpenIddictEntityFrameworkCoreOptions> options)
+        IOptionsMonitor<OpenIddictEntityFrameworkCoreOptions> options!!)
         : base(cache, context, options)
     {
     }
@@ -74,9 +74,9 @@ public class OpenIddictEntityFrameworkCoreApplicationStore<TApplication, TAuthor
     where TKey : notnull, IEquatable<TKey>
 {
     public OpenIddictEntityFrameworkCoreApplicationStore(
-        IMemoryCache cache,
-        TContext context,
-        IOptionsMonitor<OpenIddictEntityFrameworkCoreOptions> options)
+        IMemoryCache cache!!,
+        TContext context!!,
+        IOptionsMonitor<OpenIddictEntityFrameworkCoreOptions> options!!)
     {
         Cache = cache;
         Context = context;
@@ -118,37 +118,20 @@ public class OpenIddictEntityFrameworkCoreApplicationStore<TApplication, TAuthor
         => await Applications.AsQueryable().LongCountAsync(cancellationToken);
 
     /// <inheritdoc/>
-    public virtual async ValueTask<long> CountAsync<TResult>(Func<IQueryable<TApplication>, IQueryable<TResult>> query, CancellationToken cancellationToken)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return await query(Applications).LongCountAsync(cancellationToken);
-    }
+    public virtual async ValueTask<long> CountAsync<TResult>(Func<IQueryable<TApplication>, IQueryable<TResult>> query!!, CancellationToken cancellationToken)
+        => await query(Applications).LongCountAsync(cancellationToken);
 
     /// <inheritdoc/>
-    public virtual async ValueTask CreateAsync(TApplication application, CancellationToken cancellationToken)
+    public virtual async ValueTask CreateAsync(TApplication application!!, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         Context.Add(application);
 
         await Context.SaveChangesAsync(cancellationToken);
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask DeleteAsync(TApplication application, CancellationToken cancellationToken)
+    public virtual async ValueTask DeleteAsync(TApplication application!!, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         async ValueTask<IDbContextTransaction?> CreateTransactionAsync()
         {
             // Note: transactions that specify an explicit isolation level are only supported by
@@ -345,83 +328,36 @@ public class OpenIddictEntityFrameworkCoreApplicationStore<TApplication, TAuthor
 
     /// <inheritdoc/>
     public virtual async ValueTask<TResult?> GetAsync<TState, TResult>(
-        Func<IQueryable<TApplication>, TState, IQueryable<TResult>> query,
+        Func<IQueryable<TApplication>, TState, IQueryable<TResult>> query!!,
         TState state, CancellationToken cancellationToken)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return await query(Applications.AsTracking(), state).FirstOrDefaultAsync(cancellationToken);
-    }
+        => await query(Applications.AsTracking(), state).FirstOrDefaultAsync(cancellationToken);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetClientIdAsync(TApplication application, CancellationToken cancellationToken)
-    {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        return new ValueTask<string?>(application.ClientId);
-    }
+    public virtual ValueTask<string?> GetClientIdAsync(TApplication application!!, CancellationToken cancellationToken)
+        => new(application.ClientId);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetClientSecretAsync(TApplication application, CancellationToken cancellationToken)
-    {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        return new ValueTask<string?>(application.ClientSecret);
-    }
+    public virtual ValueTask<string?> GetClientSecretAsync(TApplication application!!, CancellationToken cancellationToken)
+        => new(application.ClientSecret);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetClientTypeAsync(TApplication application, CancellationToken cancellationToken)
-    {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        return new ValueTask<string?>(application.Type);
-    }
+    public virtual ValueTask<string?> GetClientTypeAsync(TApplication application!!, CancellationToken cancellationToken)
+        => new(application.Type);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetConsentTypeAsync(TApplication application, CancellationToken cancellationToken)
-    {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        return new ValueTask<string?>(application.ConsentType);
-    }
+    public virtual ValueTask<string?> GetConsentTypeAsync(TApplication application!!, CancellationToken cancellationToken)
+        => new(application.ConsentType);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetDisplayNameAsync(TApplication application, CancellationToken cancellationToken)
-    {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        return new ValueTask<string?>(application.DisplayName);
-    }
+    public virtual ValueTask<string?> GetDisplayNameAsync(TApplication application!!, CancellationToken cancellationToken)
+        => new(application.DisplayName);
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableDictionary<CultureInfo, string>> GetDisplayNamesAsync(TApplication application, CancellationToken cancellationToken)
+    public virtual ValueTask<ImmutableDictionary<CultureInfo, string>> GetDisplayNamesAsync(TApplication application!!, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         if (string.IsNullOrEmpty(application.DisplayNames))
         {
-            return new ValueTask<ImmutableDictionary<CultureInfo, string>>(ImmutableDictionary.Create<CultureInfo, string>());
+            return new(ImmutableDictionary.Create<CultureInfo, string>());
         }
 
         // Note: parsing the stringified display names is an expensive operation.
@@ -449,31 +385,19 @@ public class OpenIddictEntityFrameworkCoreApplicationStore<TApplication, TAuthor
             return builder.ToImmutable();
         });
 
-        return new ValueTask<ImmutableDictionary<CultureInfo, string>>(names);
+        return new(names);
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetIdAsync(TApplication application, CancellationToken cancellationToken)
-    {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        return new ValueTask<string?>(ConvertIdentifierToString(application.Id));
-    }
+    public virtual ValueTask<string?> GetIdAsync(TApplication application!!, CancellationToken cancellationToken)
+        => new(ConvertIdentifierToString(application.Id));
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableArray<string>> GetPermissionsAsync(TApplication application, CancellationToken cancellationToken)
+    public virtual ValueTask<ImmutableArray<string>> GetPermissionsAsync(TApplication application!!, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         if (string.IsNullOrEmpty(application.Permissions))
         {
-            return new ValueTask<ImmutableArray<string>>(ImmutableArray.Create<string>());
+            return new(ImmutableArray.Create<string>());
         }
 
         // Note: parsing the stringified permissions is an expensive operation.
@@ -501,20 +425,15 @@ public class OpenIddictEntityFrameworkCoreApplicationStore<TApplication, TAuthor
             return builder.ToImmutable();
         });
 
-        return new ValueTask<ImmutableArray<string>>(permissions);
+        return new(permissions);
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableArray<string>> GetPostLogoutRedirectUrisAsync(TApplication application, CancellationToken cancellationToken)
+    public virtual ValueTask<ImmutableArray<string>> GetPostLogoutRedirectUrisAsync(TApplication application!!, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         if (string.IsNullOrEmpty(application.PostLogoutRedirectUris))
         {
-            return new ValueTask<ImmutableArray<string>>(ImmutableArray.Create<string>());
+            return new(ImmutableArray.Create<string>());
         }
 
         // Note: parsing the stringified addresses is an expensive operation.
@@ -542,20 +461,15 @@ public class OpenIddictEntityFrameworkCoreApplicationStore<TApplication, TAuthor
             return builder.ToImmutable();
         });
 
-        return new ValueTask<ImmutableArray<string>>(addresses);
+        return new(addresses);
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableDictionary<string, JsonElement>> GetPropertiesAsync(TApplication application, CancellationToken cancellationToken)
+    public virtual ValueTask<ImmutableDictionary<string, JsonElement>> GetPropertiesAsync(TApplication application!!, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         if (string.IsNullOrEmpty(application.Properties))
         {
-            return new ValueTask<ImmutableDictionary<string, JsonElement>>(ImmutableDictionary.Create<string, JsonElement>());
+            return new(ImmutableDictionary.Create<string, JsonElement>());
         }
 
         // Note: parsing the stringified properties is an expensive operation.
@@ -577,20 +491,15 @@ public class OpenIddictEntityFrameworkCoreApplicationStore<TApplication, TAuthor
             return builder.ToImmutable();
         });
 
-        return new ValueTask<ImmutableDictionary<string, JsonElement>>(properties);
+        return new(properties);
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableArray<string>> GetRedirectUrisAsync(TApplication application, CancellationToken cancellationToken)
+    public virtual ValueTask<ImmutableArray<string>> GetRedirectUrisAsync(TApplication application!!, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         if (string.IsNullOrEmpty(application.RedirectUris))
         {
-            return new ValueTask<ImmutableArray<string>>(ImmutableArray.Create<string>());
+            return new(ImmutableArray.Create<string>());
         }
 
         // Note: parsing the stringified addresses is an expensive operation.
@@ -618,20 +527,15 @@ public class OpenIddictEntityFrameworkCoreApplicationStore<TApplication, TAuthor
             return builder.ToImmutable();
         });
 
-        return new ValueTask<ImmutableArray<string>>(addresses);
+        return new(addresses);
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableArray<string>> GetRequirementsAsync(TApplication application, CancellationToken cancellationToken)
+    public virtual ValueTask<ImmutableArray<string>> GetRequirementsAsync(TApplication application!!, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         if (string.IsNullOrEmpty(application.Requirements))
         {
-            return new ValueTask<ImmutableArray<string>>(ImmutableArray.Create<string>());
+            return new(ImmutableArray.Create<string>());
         }
 
         // Note: parsing the stringified requirements is an expensive operation.
@@ -659,7 +563,7 @@ public class OpenIddictEntityFrameworkCoreApplicationStore<TApplication, TAuthor
             return builder.ToImmutable();
         });
 
-        return new ValueTask<ImmutableArray<string>>(requirements);
+        return new(requirements);
     }
 
     /// <inheritdoc/>
@@ -667,12 +571,12 @@ public class OpenIddictEntityFrameworkCoreApplicationStore<TApplication, TAuthor
     {
         try
         {
-            return new ValueTask<TApplication>(Activator.CreateInstance<TApplication>());
+            return new(Activator.CreateInstance<TApplication>());
         }
 
         catch (MemberAccessException exception)
         {
-            return new ValueTask<TApplication>(Task.FromException<TApplication>(
+            return new(Task.FromException<TApplication>(
                 new InvalidOperationException(SR.GetResourceString(SR.ID0240), exception)));
         }
     }
@@ -697,91 +601,54 @@ public class OpenIddictEntityFrameworkCoreApplicationStore<TApplication, TAuthor
 
     /// <inheritdoc/>
     public virtual IAsyncEnumerable<TResult> ListAsync<TState, TResult>(
-        Func<IQueryable<TApplication>, TState, IQueryable<TResult>> query,
+        Func<IQueryable<TApplication>, TState, IQueryable<TResult>> query!!,
         TState state, CancellationToken cancellationToken)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return query(Applications.AsTracking(), state).AsAsyncEnumerable(cancellationToken);
-    }
+        => query(Applications.AsTracking(), state).AsAsyncEnumerable(cancellationToken);
 
     /// <inheritdoc/>
-    public virtual ValueTask SetClientIdAsync(TApplication application, string? identifier, CancellationToken cancellationToken)
+    public virtual ValueTask SetClientIdAsync(TApplication application!!, string? identifier, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         application.ClientId = identifier;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetClientSecretAsync(TApplication application, string? secret, CancellationToken cancellationToken)
+    public virtual ValueTask SetClientSecretAsync(TApplication application!!, string? secret, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         application.ClientSecret = secret;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetClientTypeAsync(TApplication application, string? type, CancellationToken cancellationToken)
+    public virtual ValueTask SetClientTypeAsync(TApplication application!!, string? type, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         application.Type = type;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetConsentTypeAsync(TApplication application, string? type, CancellationToken cancellationToken)
+    public virtual ValueTask SetConsentTypeAsync(TApplication application!!, string? type, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         application.ConsentType = type;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetDisplayNameAsync(TApplication application, string? name, CancellationToken cancellationToken)
+    public virtual ValueTask SetDisplayNameAsync(TApplication application!!, string? name, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         application.DisplayName = name;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetDisplayNamesAsync(TApplication application,
+    public virtual ValueTask SetDisplayNamesAsync(TApplication application!!,
         ImmutableDictionary<CultureInfo, string> names, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         if (names is null || names.IsEmpty)
         {
             application.DisplayNames = null;
@@ -813,13 +680,8 @@ public class OpenIddictEntityFrameworkCoreApplicationStore<TApplication, TAuthor
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetPermissionsAsync(TApplication application, ImmutableArray<string> permissions, CancellationToken cancellationToken)
+    public virtual ValueTask SetPermissionsAsync(TApplication application!!, ImmutableArray<string> permissions, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         if (permissions.IsDefaultOrEmpty)
         {
             application.Permissions = null;
@@ -850,14 +712,9 @@ public class OpenIddictEntityFrameworkCoreApplicationStore<TApplication, TAuthor
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetPostLogoutRedirectUrisAsync(TApplication application,
+    public virtual ValueTask SetPostLogoutRedirectUrisAsync(TApplication application!!,
         ImmutableArray<string> addresses, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         if (addresses.IsDefaultOrEmpty)
         {
             application.PostLogoutRedirectUris = null;
@@ -888,15 +745,10 @@ public class OpenIddictEntityFrameworkCoreApplicationStore<TApplication, TAuthor
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetPropertiesAsync(TApplication application,
+    public virtual ValueTask SetPropertiesAsync(TApplication application!!,
         ImmutableDictionary<string, JsonElement> properties, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        if (properties is null || properties.IsEmpty)
+        if (properties is not { IsEmpty: false })
         {
             application.Properties = null;
 
@@ -927,14 +779,9 @@ public class OpenIddictEntityFrameworkCoreApplicationStore<TApplication, TAuthor
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetRedirectUrisAsync(TApplication application,
+    public virtual ValueTask SetRedirectUrisAsync(TApplication application!!,
         ImmutableArray<string> addresses, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         if (addresses.IsDefaultOrEmpty)
         {
             application.RedirectUris = null;
@@ -965,13 +812,8 @@ public class OpenIddictEntityFrameworkCoreApplicationStore<TApplication, TAuthor
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetRequirementsAsync(TApplication application, ImmutableArray<string> requirements, CancellationToken cancellationToken)
+    public virtual ValueTask SetRequirementsAsync(TApplication application!!, ImmutableArray<string> requirements, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         if (requirements.IsDefaultOrEmpty)
         {
             application.Requirements = null;
@@ -1002,13 +844,8 @@ public class OpenIddictEntityFrameworkCoreApplicationStore<TApplication, TAuthor
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask UpdateAsync(TApplication application, CancellationToken cancellationToken)
+    public virtual async ValueTask UpdateAsync(TApplication application!!, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         Context.Attach(application);
 
         // Generate a new concurrency token and attach it

src/OpenIddict.EntityFrameworkCore/Stores/OpenIddictEntityFrameworkCoreAuthorizationStore.cs

@@ -30,7 +30,7 @@ public class OpenIddictEntityFrameworkCoreAuthorizationStore<TContext> :
     public OpenIddictEntityFrameworkCoreAuthorizationStore(
         IMemoryCache cache,
         TContext context,
-        IOptionsMonitor<OpenIddictEntityFrameworkCoreOptions> options)
+        IOptionsMonitor<OpenIddictEntityFrameworkCoreOptions> options!!)
         : base(cache, context, options)
     {
     }
@@ -51,7 +51,7 @@ public class OpenIddictEntityFrameworkCoreAuthorizationStore<TContext, TKey> :
     public OpenIddictEntityFrameworkCoreAuthorizationStore(
         IMemoryCache cache,
         TContext context,
-        IOptionsMonitor<OpenIddictEntityFrameworkCoreOptions> options)
+        IOptionsMonitor<OpenIddictEntityFrameworkCoreOptions> options!!)
         : base(cache, context, options)
     {
     }
@@ -73,9 +73,9 @@ public class OpenIddictEntityFrameworkCoreAuthorizationStore<TAuthorization, TAp
     where TKey : notnull, IEquatable<TKey>
 {
     public OpenIddictEntityFrameworkCoreAuthorizationStore(
-        IMemoryCache cache,
-        TContext context,
-        IOptionsMonitor<OpenIddictEntityFrameworkCoreOptions> options)
+        IMemoryCache cache!!,
+        TContext context!!,
+        IOptionsMonitor<OpenIddictEntityFrameworkCoreOptions> options!!)
     {
         Cache = cache;
         Context = context;
@@ -117,37 +117,20 @@ public class OpenIddictEntityFrameworkCoreAuthorizationStore<TAuthorization, TAp
         => await Authorizations.AsQueryable().LongCountAsync(cancellationToken);
 
     /// <inheritdoc/>
-    public virtual async ValueTask<long> CountAsync<TResult>(Func<IQueryable<TAuthorization>, IQueryable<TResult>> query, CancellationToken cancellationToken)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return await query(Authorizations).LongCountAsync(cancellationToken);
-    }
+    public virtual async ValueTask<long> CountAsync<TResult>(Func<IQueryable<TAuthorization>, IQueryable<TResult>> query!!, CancellationToken cancellationToken)
+        => await query(Authorizations).LongCountAsync(cancellationToken);
 
     /// <inheritdoc/>
-    public virtual async ValueTask CreateAsync(TAuthorization authorization, CancellationToken cancellationToken)
+    public virtual async ValueTask CreateAsync(TAuthorization authorization!!, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         Context.Add(authorization);
 
         await Context.SaveChangesAsync(cancellationToken);
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask DeleteAsync(TAuthorization authorization, CancellationToken cancellationToken)
+    public virtual async ValueTask DeleteAsync(TAuthorization authorization!!, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         async ValueTask<IDbContextTransaction?> CreateTransactionAsync()
         {
             // Note: transactions that specify an explicit isolation level are only supported by
@@ -426,13 +409,8 @@ public class OpenIddictEntityFrameworkCoreAuthorizationStore<TAuthorization, TAp
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask<string?> GetApplicationIdAsync(TAuthorization authorization, CancellationToken cancellationToken)
+    public virtual async ValueTask<string?> GetApplicationIdAsync(TAuthorization authorization!!, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         // If the application is not attached to the authorization, try to load it manually.
         if (authorization.Application is null)
         {
@@ -455,57 +433,26 @@ public class OpenIddictEntityFrameworkCoreAuthorizationStore<TAuthorization, TAp
 
     /// <inheritdoc/>
     public virtual async ValueTask<TResult?> GetAsync<TState, TResult>(
-        Func<IQueryable<TAuthorization>, TState, IQueryable<TResult>> query,
+        Func<IQueryable<TAuthorization>, TState, IQueryable<TResult>> query!!,
         TState state, CancellationToken cancellationToken)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return await query(
+        => await query(
             Authorizations.Include(authorization => authorization.Application)
                           .AsTracking(), state).FirstOrDefaultAsync(cancellationToken);
-    }
 
     /// <inheritdoc/>
-    public virtual ValueTask<DateTimeOffset?> GetCreationDateAsync(TAuthorization authorization, CancellationToken cancellationToken)
-    {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
-        if (authorization.CreationDate is null)
-        {
-            return new ValueTask<DateTimeOffset?>(result: null);
-        }
-
-        return new ValueTask<DateTimeOffset?>(DateTime.SpecifyKind(authorization.CreationDate.Value, DateTimeKind.Utc));
-    }
+    public virtual ValueTask<DateTimeOffset?> GetCreationDateAsync(TAuthorization authorization!!, CancellationToken cancellationToken)
+        => new(authorization.CreationDate is DateTime date ? DateTime.SpecifyKind(date, DateTimeKind.Utc) : null);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetIdAsync(TAuthorization authorization, CancellationToken cancellationToken)
-    {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
-        return new ValueTask<string?>(ConvertIdentifierToString(authorization.Id));
-    }
+    public virtual ValueTask<string?> GetIdAsync(TAuthorization authorization!!, CancellationToken cancellationToken)
+        => new(ConvertIdentifierToString(authorization.Id));
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableDictionary<string, JsonElement>> GetPropertiesAsync(TAuthorization authorization, CancellationToken cancellationToken)
+    public virtual ValueTask<ImmutableDictionary<string, JsonElement>> GetPropertiesAsync(TAuthorization authorization!!, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         if (string.IsNullOrEmpty(authorization.Properties))
         {
-            return new ValueTask<ImmutableDictionary<string, JsonElement>>(ImmutableDictionary.Create<string, JsonElement>());
+            return new(ImmutableDictionary.Create<string, JsonElement>());
         }
 
         // Note: parsing the stringified properties is an expensive operation.
@@ -527,20 +474,15 @@ public class OpenIddictEntityFrameworkCoreAuthorizationStore<TAuthorization, TAp
             return builder.ToImmutable();
         });
 
-        return new ValueTask<ImmutableDictionary<string, JsonElement>>(properties);
+        return new(properties);
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableArray<string>> GetScopesAsync(TAuthorization authorization, CancellationToken cancellationToken)
+    public virtual ValueTask<ImmutableArray<string>> GetScopesAsync(TAuthorization authorization!!, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         if (string.IsNullOrEmpty(authorization.Scopes))
         {
-            return new ValueTask<ImmutableArray<string>>(ImmutableArray.Create<string>());
+            return new(ImmutableArray.Create<string>());
         }
 
         // Note: parsing the stringified scopes is an expensive operation.
@@ -568,53 +510,32 @@ public class OpenIddictEntityFrameworkCoreAuthorizationStore<TAuthorization, TAp
             return builder.ToImmutable();
         });
 
-        return new ValueTask<ImmutableArray<string>>(scopes);
+        return new(scopes);
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetStatusAsync(TAuthorization authorization, CancellationToken cancellationToken)
-    {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
-        return new ValueTask<string?>(authorization.Status);
-    }
+    public virtual ValueTask<string?> GetStatusAsync(TAuthorization authorization!!, CancellationToken cancellationToken)
+        => new(authorization.Status);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetSubjectAsync(TAuthorization authorization, CancellationToken cancellationToken)
-    {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
-        return new ValueTask<string?>(authorization.Subject);
-    }
+    public virtual ValueTask<string?> GetSubjectAsync(TAuthorization authorization!!, CancellationToken cancellationToken)
+        => new(authorization.Subject);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetTypeAsync(TAuthorization authorization, CancellationToken cancellationToken)
-    {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
-        return new ValueTask<string?>(authorization.Type);
-    }
+    public virtual ValueTask<string?> GetTypeAsync(TAuthorization authorization!!, CancellationToken cancellationToken)
+        => new(authorization.Type);
 
     /// <inheritdoc/>
     public virtual ValueTask<TAuthorization> InstantiateAsync(CancellationToken cancellationToken)
     {
         try
         {
-            return new ValueTask<TAuthorization>(Activator.CreateInstance<TAuthorization>());
+            return new(Activator.CreateInstance<TAuthorization>());
         }
 
         catch (MemberAccessException exception)
         {
-            return new ValueTask<TAuthorization>(Task.FromException<TAuthorization>(
+            return new(Task.FromException<TAuthorization>(
                 new InvalidOperationException(SR.GetResourceString(SR.ID0242), exception)));
         }
     }
@@ -641,14 +562,9 @@ public class OpenIddictEntityFrameworkCoreAuthorizationStore<TAuthorization, TAp
 
     /// <inheritdoc/>
     public virtual IAsyncEnumerable<TResult> ListAsync<TState, TResult>(
-        Func<IQueryable<TAuthorization>, TState, IQueryable<TResult>> query,
+        Func<IQueryable<TAuthorization>, TState, IQueryable<TResult>> query!!,
         TState state, CancellationToken cancellationToken)
     {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
         return query(
             Authorizations.Include(authorization => authorization.Application)
                           .AsTracking(), state).AsAsyncEnumerable(cancellationToken);
@@ -746,14 +662,9 @@ public class OpenIddictEntityFrameworkCoreAuthorizationStore<TAuthorization, TAp
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask SetApplicationIdAsync(TAuthorization authorization,
+    public virtual async ValueTask SetApplicationIdAsync(TAuthorization authorization!!,
         string? identifier, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         if (!string.IsNullOrEmpty(identifier))
         {
             var key = ConvertIdentifierFromString(identifier);
@@ -792,29 +703,19 @@ public class OpenIddictEntityFrameworkCoreAuthorizationStore<TAuthorization, TAp
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetCreationDateAsync(TAuthorization authorization,
+    public virtual ValueTask SetCreationDateAsync(TAuthorization authorization!!,
         DateTimeOffset? date, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         authorization.CreationDate = date?.UtcDateTime;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetPropertiesAsync(TAuthorization authorization,
+    public virtual ValueTask SetPropertiesAsync(TAuthorization authorization!!,
         ImmutableDictionary<string, JsonElement> properties, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
-        if (properties is null || properties.IsEmpty)
+        if (properties is not { IsEmpty: false })
         {
             authorization.Properties = null;
 
@@ -845,14 +746,9 @@ public class OpenIddictEntityFrameworkCoreAuthorizationStore<TAuthorization, TAp
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetScopesAsync(TAuthorization authorization,
+    public virtual ValueTask SetScopesAsync(TAuthorization authorization!!,
         ImmutableArray<string> scopes, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         if (scopes.IsDefaultOrEmpty)
         {
             authorization.Scopes = null;
@@ -883,55 +779,35 @@ public class OpenIddictEntityFrameworkCoreAuthorizationStore<TAuthorization, TAp
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetStatusAsync(TAuthorization authorization,
+    public virtual ValueTask SetStatusAsync(TAuthorization authorization!!,
         string? status, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         authorization.Status = status;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetSubjectAsync(TAuthorization authorization,
+    public virtual ValueTask SetSubjectAsync(TAuthorization authorization!!,
         string? subject, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         authorization.Subject = subject;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetTypeAsync(TAuthorization authorization,
+    public virtual ValueTask SetTypeAsync(TAuthorization authorization!!,
         string? type, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         authorization.Type = type;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask UpdateAsync(TAuthorization authorization, CancellationToken cancellationToken)
+    public virtual async ValueTask UpdateAsync(TAuthorization authorization!!, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         Context.Attach(authorization);
 
         // Generate a new concurrency token and attach it

src/OpenIddict.EntityFrameworkCore/Stores/OpenIddictEntityFrameworkCoreScopeStore.cs

@@ -27,7 +27,7 @@ public class OpenIddictEntityFrameworkCoreScopeStore<TContext> : OpenIddictEntit
     public OpenIddictEntityFrameworkCoreScopeStore(
         IMemoryCache cache,
         TContext context,
-        IOptionsMonitor<OpenIddictEntityFrameworkCoreOptions> options)
+        IOptionsMonitor<OpenIddictEntityFrameworkCoreOptions> options!!)
         : base(cache, context, options)
     {
     }
@@ -45,7 +45,7 @@ public class OpenIddictEntityFrameworkCoreScopeStore<TContext, TKey> : OpenIddic
     public OpenIddictEntityFrameworkCoreScopeStore(
         IMemoryCache cache,
         TContext context,
-        IOptionsMonitor<OpenIddictEntityFrameworkCoreOptions> options)
+        IOptionsMonitor<OpenIddictEntityFrameworkCoreOptions> options!!)
         : base(cache, context, options)
     {
     }
@@ -63,9 +63,9 @@ public class OpenIddictEntityFrameworkCoreScopeStore<TScope, TContext, TKey> : I
     where TKey : notnull, IEquatable<TKey>
 {
     public OpenIddictEntityFrameworkCoreScopeStore(
-        IMemoryCache cache,
-        TContext context,
-        IOptionsMonitor<OpenIddictEntityFrameworkCoreOptions> options)
+        IMemoryCache cache!!,
+        TContext context!!,
+        IOptionsMonitor<OpenIddictEntityFrameworkCoreOptions> options!!)
     {
         Cache = cache;
         Context = context;
@@ -97,37 +97,20 @@ public class OpenIddictEntityFrameworkCoreScopeStore<TScope, TContext, TKey> : I
         => await Scopes.AsQueryable().LongCountAsync(cancellationToken);
 
     /// <inheritdoc/>
-    public virtual async ValueTask<long> CountAsync<TResult>(Func<IQueryable<TScope>, IQueryable<TResult>> query, CancellationToken cancellationToken)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return await query(Scopes).LongCountAsync(cancellationToken);
-    }
+    public virtual async ValueTask<long> CountAsync<TResult>(Func<IQueryable<TScope>, IQueryable<TResult>> query!!, CancellationToken cancellationToken)
+        => await query(Scopes).LongCountAsync(cancellationToken);
 
     /// <inheritdoc/>
-    public virtual async ValueTask CreateAsync(TScope scope, CancellationToken cancellationToken)
+    public virtual async ValueTask CreateAsync(TScope scope!!, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         Scopes.Add(scope);
 
         await Context.SaveChangesAsync(cancellationToken);
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask DeleteAsync(TScope scope, CancellationToken cancellationToken)
+    public virtual async ValueTask DeleteAsync(TScope scope!!, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         Context.Remove(scope);
 
         try
@@ -176,7 +159,7 @@ public class OpenIddictEntityFrameworkCoreScopeStore<TScope, TContext, TKey> : I
     public virtual IAsyncEnumerable<TScope> FindByNamesAsync(
         ImmutableArray<string> names, CancellationToken cancellationToken)
     {
-        if (names.Any(name => string.IsNullOrEmpty(name)))
+        if (names.Any(string.IsNullOrEmpty))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0203), nameof(names));
         }
@@ -224,39 +207,20 @@ public class OpenIddictEntityFrameworkCoreScopeStore<TScope, TContext, TKey> : I
 
     /// <inheritdoc/>
     public virtual async ValueTask<TResult?> GetAsync<TState, TResult>(
-        Func<IQueryable<TScope>, TState, IQueryable<TResult>> query,
+        Func<IQueryable<TScope>, TState, IQueryable<TResult>> query!!,
         TState state, CancellationToken cancellationToken)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return await query(Scopes.AsTracking(), state).FirstOrDefaultAsync(cancellationToken);
-    }
+        => await query(Scopes.AsTracking(), state).FirstOrDefaultAsync(cancellationToken);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetDescriptionAsync(TScope scope, CancellationToken cancellationToken)
-    {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
-        return new ValueTask<string?>(scope.Description);
-    }
+    public virtual ValueTask<string?> GetDescriptionAsync(TScope scope!!, CancellationToken cancellationToken)
+        => new(scope.Description);
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableDictionary<CultureInfo, string>> GetDescriptionsAsync(TScope scope, CancellationToken cancellationToken)
+    public virtual ValueTask<ImmutableDictionary<CultureInfo, string>> GetDescriptionsAsync(TScope scope!!, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         if (string.IsNullOrEmpty(scope.Descriptions))
         {
-            return new ValueTask<ImmutableDictionary<CultureInfo, string>>(ImmutableDictionary.Create<CultureInfo, string>());
+            return new(ImmutableDictionary.Create<CultureInfo, string>());
         }
 
         // Note: parsing the stringified descriptions is an expensive operation.
@@ -284,31 +248,19 @@ public class OpenIddictEntityFrameworkCoreScopeStore<TScope, TContext, TKey> : I
             return builder.ToImmutable();
         });
 
-        return new ValueTask<ImmutableDictionary<CultureInfo, string>>(descriptions);
+        return new(descriptions);
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetDisplayNameAsync(TScope scope, CancellationToken cancellationToken)
-    {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
-        return new ValueTask<string?>(scope.DisplayName);
-    }
+    public virtual ValueTask<string?> GetDisplayNameAsync(TScope scope!!, CancellationToken cancellationToken)
+        => new(scope.DisplayName);
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableDictionary<CultureInfo, string>> GetDisplayNamesAsync(TScope scope, CancellationToken cancellationToken)
+    public virtual ValueTask<ImmutableDictionary<CultureInfo, string>> GetDisplayNamesAsync(TScope scope!!, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         if (string.IsNullOrEmpty(scope.DisplayNames))
         {
-            return new ValueTask<ImmutableDictionary<CultureInfo, string>>(ImmutableDictionary.Create<CultureInfo, string>());
+            return new(ImmutableDictionary.Create<CultureInfo, string>());
         }
 
         // Note: parsing the stringified display names is an expensive operation.
@@ -336,42 +288,23 @@ public class OpenIddictEntityFrameworkCoreScopeStore<TScope, TContext, TKey> : I
             return builder.ToImmutable();
         });
 
-        return new ValueTask<ImmutableDictionary<CultureInfo, string>>(names);
+        return new(names);
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetIdAsync(TScope scope, CancellationToken cancellationToken)
-    {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
-        return new ValueTask<string?>(ConvertIdentifierToString(scope.Id));
-    }
+    public virtual ValueTask<string?> GetIdAsync(TScope scope!!, CancellationToken cancellationToken)
+        => new(ConvertIdentifierToString(scope.Id));
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetNameAsync(TScope scope, CancellationToken cancellationToken)
-    {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
-        return new ValueTask<string?>(scope.Name);
-    }
+    public virtual ValueTask<string?> GetNameAsync(TScope scope!!, CancellationToken cancellationToken)
+        => new(scope.Name);
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableDictionary<string, JsonElement>> GetPropertiesAsync(TScope scope, CancellationToken cancellationToken)
+    public virtual ValueTask<ImmutableDictionary<string, JsonElement>> GetPropertiesAsync(TScope scope!!, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         if (string.IsNullOrEmpty(scope.Properties))
         {
-            return new ValueTask<ImmutableDictionary<string, JsonElement>>(ImmutableDictionary.Create<string, JsonElement>());
+            return new(ImmutableDictionary.Create<string, JsonElement>());
         }
 
         // Note: parsing the stringified properties is an expensive operation.
@@ -393,20 +326,15 @@ public class OpenIddictEntityFrameworkCoreScopeStore<TScope, TContext, TKey> : I
             return builder.ToImmutable();
         });
 
-        return new ValueTask<ImmutableDictionary<string, JsonElement>>(properties);
+        return new(properties);
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableArray<string>> GetResourcesAsync(TScope scope, CancellationToken cancellationToken)
+    public virtual ValueTask<ImmutableArray<string>> GetResourcesAsync(TScope scope!!, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         if (string.IsNullOrEmpty(scope.Resources))
         {
-            return new ValueTask<ImmutableArray<string>>(ImmutableArray.Create<string>());
+            return new(ImmutableArray.Create<string>());
         }
 
         // Note: parsing the stringified resources is an expensive operation.
@@ -434,7 +362,7 @@ public class OpenIddictEntityFrameworkCoreScopeStore<TScope, TContext, TKey> : I
             return builder.ToImmutable();
         });
 
-        return new ValueTask<ImmutableArray<string>>(resources);
+        return new(resources);
     }
 
     /// <inheritdoc/>
@@ -442,12 +370,12 @@ public class OpenIddictEntityFrameworkCoreScopeStore<TScope, TContext, TKey> : I
     {
         try
         {
-            return new ValueTask<TScope>(Activator.CreateInstance<TScope>());
+            return new(Activator.CreateInstance<TScope>());
         }
 
         catch (MemberAccessException exception)
         {
-            return new ValueTask<TScope>(Task.FromException<TScope>(
+            return new(Task.FromException<TScope>(
                 new InvalidOperationException(SR.GetResourceString(SR.ID0246), exception)));
         }
     }
@@ -472,39 +400,22 @@ public class OpenIddictEntityFrameworkCoreScopeStore<TScope, TContext, TKey> : I
 
     /// <inheritdoc/>
     public virtual IAsyncEnumerable<TResult> ListAsync<TState, TResult>(
-        Func<IQueryable<TScope>, TState, IQueryable<TResult>> query,
+        Func<IQueryable<TScope>, TState, IQueryable<TResult>> query!!,
         TState state, CancellationToken cancellationToken)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return query(Scopes.AsTracking(), state).AsAsyncEnumerable(cancellationToken);
-    }
+        => query(Scopes.AsTracking(), state).AsAsyncEnumerable(cancellationToken);
 
     /// <inheritdoc/>
-    public virtual ValueTask SetDescriptionAsync(TScope scope, string? description, CancellationToken cancellationToken)
+    public virtual ValueTask SetDescriptionAsync(TScope scope!!, string? description, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         scope.Description = description;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetDescriptionsAsync(TScope scope,
+    public virtual ValueTask SetDescriptionsAsync(TScope scope!!,
         ImmutableDictionary<CultureInfo, string> descriptions, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         if (descriptions is null || descriptions.IsEmpty)
         {
             scope.Descriptions = null;
@@ -536,27 +447,17 @@ public class OpenIddictEntityFrameworkCoreScopeStore<TScope, TContext, TKey> : I
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetDisplayNameAsync(TScope scope, string? name, CancellationToken cancellationToken)
+    public virtual ValueTask SetDisplayNameAsync(TScope scope!!, string? name, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         scope.DisplayName = name;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetDisplayNamesAsync(TScope scope,
+    public virtual ValueTask SetDisplayNamesAsync(TScope scope!!,
         ImmutableDictionary<CultureInfo, string> names, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         if (names is null || names.IsEmpty)
         {
             scope.DisplayNames = null;
@@ -588,28 +489,18 @@ public class OpenIddictEntityFrameworkCoreScopeStore<TScope, TContext, TKey> : I
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetNameAsync(TScope scope, string? name, CancellationToken cancellationToken)
+    public virtual ValueTask SetNameAsync(TScope scope!!, string? name, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         scope.Name = name;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetPropertiesAsync(TScope scope,
+    public virtual ValueTask SetPropertiesAsync(TScope scope!!,
         ImmutableDictionary<string, JsonElement> properties, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
-        if (properties is null || properties.IsEmpty)
+        if (properties is not { IsEmpty: false })
         {
             scope.Properties = null;
 
@@ -640,13 +531,8 @@ public class OpenIddictEntityFrameworkCoreScopeStore<TScope, TContext, TKey> : I
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetResourcesAsync(TScope scope, ImmutableArray<string> resources, CancellationToken cancellationToken)
+    public virtual ValueTask SetResourcesAsync(TScope scope!!, ImmutableArray<string> resources, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         if (resources.IsDefaultOrEmpty)
         {
             scope.Resources = null;
@@ -677,13 +563,8 @@ public class OpenIddictEntityFrameworkCoreScopeStore<TScope, TContext, TKey> : I
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask UpdateAsync(TScope scope, CancellationToken cancellationToken)
+    public virtual async ValueTask UpdateAsync(TScope scope!!, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         Context.Attach(scope);
 
         // Generate a new concurrency token and attach it

src/OpenIddict.EntityFrameworkCore/Stores/OpenIddictEntityFrameworkCoreTokenStore.cs

@@ -29,7 +29,7 @@ public class OpenIddictEntityFrameworkCoreTokenStore<TContext> :
     public OpenIddictEntityFrameworkCoreTokenStore(
         IMemoryCache cache,
         TContext context,
-        IOptionsMonitor<OpenIddictEntityFrameworkCoreOptions> options)
+        IOptionsMonitor<OpenIddictEntityFrameworkCoreOptions> options!!)
         : base(cache, context, options)
     {
     }
@@ -50,7 +50,7 @@ public class OpenIddictEntityFrameworkCoreTokenStore<TContext, TKey> :
     public OpenIddictEntityFrameworkCoreTokenStore(
         IMemoryCache cache,
         TContext context,
-        IOptionsMonitor<OpenIddictEntityFrameworkCoreOptions> options)
+        IOptionsMonitor<OpenIddictEntityFrameworkCoreOptions> options!!)
         : base(cache, context, options)
     {
     }
@@ -72,9 +72,9 @@ public class OpenIddictEntityFrameworkCoreTokenStore<TToken, TApplication, TAuth
     where TKey : notnull, IEquatable<TKey>
 {
     public OpenIddictEntityFrameworkCoreTokenStore(
-        IMemoryCache cache,
-        TContext context,
-        IOptionsMonitor<OpenIddictEntityFrameworkCoreOptions> options)
+        IMemoryCache cache!!,
+        TContext context!!,
+        IOptionsMonitor<OpenIddictEntityFrameworkCoreOptions> options!!)
     {
         Cache = cache;
         Context = context;
@@ -116,37 +116,20 @@ public class OpenIddictEntityFrameworkCoreTokenStore<TToken, TApplication, TAuth
         => await Tokens.AsQueryable().LongCountAsync(cancellationToken);
 
     /// <inheritdoc/>
-    public virtual async ValueTask<long> CountAsync<TResult>(Func<IQueryable<TToken>, IQueryable<TResult>> query, CancellationToken cancellationToken)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return await query(Tokens).LongCountAsync(cancellationToken);
-    }
+    public virtual async ValueTask<long> CountAsync<TResult>(Func<IQueryable<TToken>, IQueryable<TResult>> query!!, CancellationToken cancellationToken)
+        => await query(Tokens).LongCountAsync(cancellationToken);
 
     /// <inheritdoc/>
-    public virtual async ValueTask CreateAsync(TToken token, CancellationToken cancellationToken)
+    public virtual async ValueTask CreateAsync(TToken token!!, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         Context.Add(token);
 
         await Context.SaveChangesAsync(cancellationToken);
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask DeleteAsync(TToken token, CancellationToken cancellationToken)
+    public virtual async ValueTask DeleteAsync(TToken token!!, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         Context.Remove(token);
 
         try
@@ -350,13 +333,8 @@ public class OpenIddictEntityFrameworkCoreTokenStore<TToken, TApplication, TAuth
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask<string?> GetApplicationIdAsync(TToken token, CancellationToken cancellationToken)
+    public virtual async ValueTask<string?> GetApplicationIdAsync(TToken token!!, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         // If the application is not attached to the token, try to load it manually.
         if (token.Application is null)
         {
@@ -379,27 +357,15 @@ public class OpenIddictEntityFrameworkCoreTokenStore<TToken, TApplication, TAuth
 
     /// <inheritdoc/>
     public virtual async ValueTask<TResult?> GetAsync<TState, TResult>(
-        Func<IQueryable<TToken>, TState, IQueryable<TResult>> query,
+        Func<IQueryable<TToken>, TState, IQueryable<TResult>> query!!,
         TState state, CancellationToken cancellationToken)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return await query(Tokens.Include(token => token.Application)
+        => await query(Tokens.Include(token => token.Application)
             .Include(token => token.Authorization)
             .AsTracking(), state).FirstOrDefaultAsync(cancellationToken);
-    }
 
     /// <inheritdoc/>
-    public virtual async ValueTask<string?> GetAuthorizationIdAsync(TToken token, CancellationToken cancellationToken)
+    public virtual async ValueTask<string?> GetAuthorizationIdAsync(TToken token!!, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         // If the authorization is not attached to the token, try to load it manually.
         if (token.Authorization is null)
         {
@@ -421,70 +387,27 @@ public class OpenIddictEntityFrameworkCoreTokenStore<TToken, TApplication, TAuth
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<DateTimeOffset?> GetCreationDateAsync(TToken token, CancellationToken cancellationToken)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        if (token.CreationDate is null)
-        {
-            return new ValueTask<DateTimeOffset?>(result: null);
-        }
-
-        return new ValueTask<DateTimeOffset?>(DateTime.SpecifyKind(token.CreationDate.Value, DateTimeKind.Utc));
-    }
+    public virtual ValueTask<DateTimeOffset?> GetCreationDateAsync(TToken token!!, CancellationToken cancellationToken)
+        => new(token.CreationDate is DateTime date ? DateTime.SpecifyKind(date, DateTimeKind.Utc) : null);
 
     /// <inheritdoc/>
-    public virtual ValueTask<DateTimeOffset?> GetExpirationDateAsync(TToken token, CancellationToken cancellationToken)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        if (token.ExpirationDate is null)
-        {
-            return new ValueTask<DateTimeOffset?>(result: null);
-        }
-
-        return new ValueTask<DateTimeOffset?>(DateTime.SpecifyKind(token.ExpirationDate.Value, DateTimeKind.Utc));
-    }
+    public virtual ValueTask<DateTimeOffset?> GetExpirationDateAsync(TToken token!!, CancellationToken cancellationToken)
+        => new(token.ExpirationDate is DateTime date ? DateTime.SpecifyKind(date, DateTimeKind.Utc) : null);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetIdAsync(TToken token, CancellationToken cancellationToken)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        return new ValueTask<string?>(ConvertIdentifierToString(token.Id));
-    }
+    public virtual ValueTask<string?> GetIdAsync(TToken token!!, CancellationToken cancellationToken)
+        => new(ConvertIdentifierToString(token.Id));
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetPayloadAsync(TToken token, CancellationToken cancellationToken)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        return new ValueTask<string?>(token.Payload);
-    }
+    public virtual ValueTask<string?> GetPayloadAsync(TToken token!!, CancellationToken cancellationToken)
+        => new(token.Payload);
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableDictionary<string, JsonElement>> GetPropertiesAsync(TToken token, CancellationToken cancellationToken)
+    public virtual ValueTask<ImmutableDictionary<string, JsonElement>> GetPropertiesAsync(TToken token!!, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         if (string.IsNullOrEmpty(token.Properties))
         {
-            return new ValueTask<ImmutableDictionary<string, JsonElement>>(ImmutableDictionary.Create<string, JsonElement>());
+            return new(ImmutableDictionary.Create<string, JsonElement>());
         }
 
         // Note: parsing the stringified properties is an expensive operation.
@@ -506,80 +429,40 @@ public class OpenIddictEntityFrameworkCoreTokenStore<TToken, TApplication, TAuth
             return builder.ToImmutable();
         });
 
-        return new ValueTask<ImmutableDictionary<string, JsonElement>>(properties);
+        return new(properties);
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<DateTimeOffset?> GetRedemptionDateAsync(TToken token, CancellationToken cancellationToken)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        if (token.RedemptionDate is null)
-        {
-            return new ValueTask<DateTimeOffset?>(result: null);
-        }
-
-        return new ValueTask<DateTimeOffset?>(DateTime.SpecifyKind(token.RedemptionDate.Value, DateTimeKind.Utc));
-    }
+    public virtual ValueTask<DateTimeOffset?> GetRedemptionDateAsync(TToken token!!, CancellationToken cancellationToken)
+        => new(token.RedemptionDate is DateTime date ? DateTime.SpecifyKind(date, DateTimeKind.Utc) : null);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetReferenceIdAsync(TToken token, CancellationToken cancellationToken)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        return new ValueTask<string?>(token.ReferenceId);
-    }
+    public virtual ValueTask<string?> GetReferenceIdAsync(TToken token!!, CancellationToken cancellationToken)
+        => new(token.ReferenceId);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetStatusAsync(TToken token, CancellationToken cancellationToken)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        return new ValueTask<string?>(token.Status);
-    }
+    public virtual ValueTask<string?> GetStatusAsync(TToken token!!, CancellationToken cancellationToken)
+        => new(token.Status);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetSubjectAsync(TToken token, CancellationToken cancellationToken)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        return new ValueTask<string?>(token.Subject);
-    }
+    public virtual ValueTask<string?> GetSubjectAsync(TToken token!!, CancellationToken cancellationToken)
+        => new(token.Subject);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetTypeAsync(TToken token, CancellationToken cancellationToken)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        return new ValueTask<string?>(token.Type);
-    }
+    public virtual ValueTask<string?> GetTypeAsync(TToken token!!, CancellationToken cancellationToken)
+        => new(token.Type);
 
     /// <inheritdoc/>
     public virtual ValueTask<TToken> InstantiateAsync(CancellationToken cancellationToken)
     {
         try
         {
-            return new ValueTask<TToken>(Activator.CreateInstance<TToken>());
+            return new(Activator.CreateInstance<TToken>());
         }
 
         catch (MemberAccessException exception)
         {
-            return new ValueTask<TToken>(Task.FromException<TToken>(
+            return new(Task.FromException<TToken>(
                 new InvalidOperationException(SR.GetResourceString(SR.ID0248), exception)));
         }
     }
@@ -607,19 +490,12 @@ public class OpenIddictEntityFrameworkCoreTokenStore<TToken, TApplication, TAuth
 
     /// <inheritdoc/>
     public virtual IAsyncEnumerable<TResult> ListAsync<TState, TResult>(
-        Func<IQueryable<TToken>, TState, IQueryable<TResult>> query,
+        Func<IQueryable<TToken>, TState, IQueryable<TResult>> query!!,
         TState state, CancellationToken cancellationToken)
-    {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
-        return query(
+        => query(
             Tokens.Include(token => token.Application)
                   .Include(token => token.Authorization)
                   .AsTracking(), state).AsAsyncEnumerable(cancellationToken);
-    }
 
     /// <inheritdoc/>
     public virtual async ValueTask PruneAsync(DateTimeOffset threshold, CancellationToken cancellationToken)
@@ -710,13 +586,8 @@ public class OpenIddictEntityFrameworkCoreTokenStore<TToken, TApplication, TAuth
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask SetApplicationIdAsync(TToken token, string? identifier, CancellationToken cancellationToken)
+    public virtual async ValueTask SetApplicationIdAsync(TToken token!!, string? identifier, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         if (!string.IsNullOrEmpty(identifier))
         {
             var key = ConvertIdentifierFromString(identifier);
@@ -755,13 +626,8 @@ public class OpenIddictEntityFrameworkCoreTokenStore<TToken, TApplication, TAuth
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask SetAuthorizationIdAsync(TToken token, string? identifier, CancellationToken cancellationToken)
+    public virtual async ValueTask SetAuthorizationIdAsync(TToken token!!, string? identifier, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         if (!string.IsNullOrEmpty(identifier))
         {
             var key = ConvertIdentifierFromString(identifier);
@@ -800,54 +666,34 @@ public class OpenIddictEntityFrameworkCoreTokenStore<TToken, TApplication, TAuth
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetCreationDateAsync(TToken token, DateTimeOffset? date, CancellationToken cancellationToken)
+    public virtual ValueTask SetCreationDateAsync(TToken token!!, DateTimeOffset? date, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         token.CreationDate = date?.UtcDateTime;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetExpirationDateAsync(TToken token, DateTimeOffset? date, CancellationToken cancellationToken)
+    public virtual ValueTask SetExpirationDateAsync(TToken token!!, DateTimeOffset? date, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         token.ExpirationDate = date?.UtcDateTime;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetPayloadAsync(TToken token, string? payload, CancellationToken cancellationToken)
+    public virtual ValueTask SetPayloadAsync(TToken token!!, string? payload, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         token.Payload = payload;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetPropertiesAsync(TToken token,
+    public virtual ValueTask SetPropertiesAsync(TToken token!!,
         ImmutableDictionary<string, JsonElement> properties, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        if (properties is null || properties.IsEmpty)
+        if (properties is not { IsEmpty: false })
         {
             token.Properties = null;
 
@@ -878,78 +724,48 @@ public class OpenIddictEntityFrameworkCoreTokenStore<TToken, TApplication, TAuth
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetRedemptionDateAsync(TToken token, DateTimeOffset? date, CancellationToken cancellationToken)
+    public virtual ValueTask SetRedemptionDateAsync(TToken token!!, DateTimeOffset? date, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         token.RedemptionDate = date?.UtcDateTime;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetReferenceIdAsync(TToken token, string? identifier, CancellationToken cancellationToken)
+    public virtual ValueTask SetReferenceIdAsync(TToken token!!, string? identifier, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         token.ReferenceId = identifier;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetStatusAsync(TToken token, string? status, CancellationToken cancellationToken)
+    public virtual ValueTask SetStatusAsync(TToken token!!, string? status, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         token.Status = status;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetSubjectAsync(TToken token, string? subject, CancellationToken cancellationToken)
+    public virtual ValueTask SetSubjectAsync(TToken token!!, string? subject, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         token.Subject = subject;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetTypeAsync(TToken token, string? type, CancellationToken cancellationToken)
+    public virtual ValueTask SetTypeAsync(TToken token!!, string? type, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         token.Type = type;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask UpdateAsync(TToken token, CancellationToken cancellationToken)
+    public virtual async ValueTask UpdateAsync(TToken token!!, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         Context.Attach(token);
 
         // Generate a new concurrency token and attach it

src/OpenIddict.MongoDb/OpenIddictMongoDbBuilder.cs

@@ -20,8 +20,8 @@ public class OpenIddictMongoDbBuilder
     /// Initializes a new instance of <see cref="OpenIddictMongoDbBuilder"/>.
     /// </summary>
     /// <param name="services">The services collection.</param>
-    public OpenIddictMongoDbBuilder(IServiceCollection services)
-        => Services = services ?? throw new ArgumentNullException(nameof(services));
+    public OpenIddictMongoDbBuilder(IServiceCollection services!!)
+        => Services = services;
 
     /// <summary>
     /// Gets the services collection.
@@ -35,13 +35,8 @@ public class OpenIddictMongoDbBuilder
     /// <param name="configuration">The delegate used to configure the OpenIddict options.</param>
     /// <remarks>This extension can be safely called multiple times.</remarks>
     /// <returns>The <see cref="OpenIddictMongoDbBuilder"/>.</returns>
-    public OpenIddictMongoDbBuilder Configure(Action<OpenIddictMongoDbOptions> configuration)
+    public OpenIddictMongoDbBuilder Configure(Action<OpenIddictMongoDbOptions> configuration!!)
     {
-        if (configuration is null)
-        {
-            throw new ArgumentNullException(nameof(configuration));
-        }
-
         Services.Configure(configuration);
 
         return this;
@@ -161,13 +156,8 @@ public class OpenIddictMongoDbBuilder
     /// </summary>
     /// <param name="database">The <see cref="IMongoDatabase"/>.</param>
     /// <returns>The <see cref="OpenIddictMongoDbBuilder"/>.</returns>
-    public OpenIddictMongoDbBuilder UseDatabase(IMongoDatabase database)
+    public OpenIddictMongoDbBuilder UseDatabase(IMongoDatabase database!!)
     {
-        if (database is null)
-        {
-            throw new ArgumentNullException(nameof(database));
-        }
-
         return Configure(options => options.Database = database);
     }
 

src/OpenIddict.MongoDb/OpenIddictMongoDbContext.cs

@@ -16,8 +16,8 @@ public class OpenIddictMongoDbContext : IOpenIddictMongoDbContext
     private readonly IServiceProvider _provider;
 
     public OpenIddictMongoDbContext(
-        IOptionsMonitor<OpenIddictMongoDbOptions> options,
-        IServiceProvider provider)
+        IOptionsMonitor<OpenIddictMongoDbOptions> options!!,
+        IServiceProvider provider!!)
     {
         _options = options;
         _provider = provider;
@@ -28,7 +28,7 @@ public class OpenIddictMongoDbContext : IOpenIddictMongoDbContext
     {
         if (cancellationToken.IsCancellationRequested)
         {
-            return new ValueTask<IMongoDatabase>(Task.FromCanceled<IMongoDatabase>(cancellationToken));
+            return new(Task.FromCanceled<IMongoDatabase>(cancellationToken));
         }
 
         var database = _options.CurrentValue.Database;
@@ -39,10 +39,10 @@ public class OpenIddictMongoDbContext : IOpenIddictMongoDbContext
 
         if (database is null)
         {
-            return new ValueTask<IMongoDatabase>(Task.FromException<IMongoDatabase>(
+            return new(Task.FromException<IMongoDatabase>(
                 new InvalidOperationException(SR.GetResourceString(SR.ID0262))));
         }
 
-        return new ValueTask<IMongoDatabase>(database);
+        return new(database);
     }
 }

src/OpenIddict.MongoDb/OpenIddictMongoDbExtensions.cs

@@ -22,13 +22,8 @@ public static class OpenIddictMongoDbExtensions
     /// <param name="builder">The services builder used by OpenIddict to register new services.</param>
     /// <remarks>This extension can be safely called multiple times.</remarks>
     /// <returns>The <see cref="OpenIddictMongoDbBuilder"/>.</returns>
-    public static OpenIddictMongoDbBuilder UseMongoDb(this OpenIddictCoreBuilder builder)
+    public static OpenIddictMongoDbBuilder UseMongoDb(this OpenIddictCoreBuilder builder!!)
     {
-        if (builder is null)
-        {
-            throw new ArgumentNullException(nameof(builder));
-        }
-
         // Note: Mongo uses simple binary comparison checks by default so the additional
         // query filtering applied by the default OpenIddict managers can be safely disabled.
         builder.DisableAdditionalFiltering();
@@ -64,18 +59,8 @@ public static class OpenIddictMongoDbExtensions
     /// <remarks>This extension can be safely called multiple times.</remarks>
     /// <returns>The <see cref="OpenIddictCoreBuilder"/>.</returns>
     public static OpenIddictCoreBuilder UseMongoDb(
-        this OpenIddictCoreBuilder builder, Action<OpenIddictMongoDbBuilder> configuration)
+        this OpenIddictCoreBuilder builder!!, Action<OpenIddictMongoDbBuilder> configuration!!)
     {
-        if (builder is null)
-        {
-            throw new ArgumentNullException(nameof(builder));
-        }
-
-        if (configuration is null)
-        {
-            throw new ArgumentNullException(nameof(configuration));
-        }
-
         configuration(builder.UseMongoDb());
 
         return builder;

src/OpenIddict.MongoDb/OpenIddictMongoDbHelpers.cs

@@ -20,13 +20,8 @@ internal static class OpenIddictMongoDbHelpers
     /// <param name="source">The query source.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns>The streamed async enumeration containing the results.</returns>
-    internal static IAsyncEnumerable<T> ToAsyncEnumerable<T>(this IAsyncCursorSource<T> source, CancellationToken cancellationToken)
+    internal static IAsyncEnumerable<T> ToAsyncEnumerable<T>(this IAsyncCursorSource<T> source!!, CancellationToken cancellationToken)
     {
-        if (source is null)
-        {
-            throw new ArgumentNullException(nameof(source));
-        }
-
         return ExecuteAsync(source, cancellationToken);
 
         static async IAsyncEnumerable<T> ExecuteAsync(IAsyncCursorSource<T> source, [EnumeratorCancellation] CancellationToken cancellationToken)
@@ -50,13 +45,6 @@ internal static class OpenIddictMongoDbHelpers
     /// <param name="source">The query source.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns>The streamed async enumeration containing the results.</returns>
-    internal static IAsyncEnumerable<T> ToAsyncEnumerable<T>(this IQueryable<T> source, CancellationToken cancellationToken)
-    {
-        if (source is null)
-        {
-            throw new ArgumentNullException(nameof(source));
-        }
-
-        return ((IAsyncCursorSource<T>) source).ToAsyncEnumerable(cancellationToken);
-    }
+    internal static IAsyncEnumerable<T> ToAsyncEnumerable<T>(this IQueryable<T> source!!, CancellationToken cancellationToken)
+        => ((IAsyncCursorSource<T>) source).ToAsyncEnumerable(cancellationToken);
 }

src/OpenIddict.MongoDb/Resolvers/OpenIddictMongoDbApplicationStoreResolver.cs

@@ -18,7 +18,7 @@ public class OpenIddictMongoDbApplicationStoreResolver : IOpenIddictApplicationS
     private readonly ConcurrentDictionary<Type, Type> _cache = new ConcurrentDictionary<Type, Type>();
     private readonly IServiceProvider _provider;
 
-    public OpenIddictMongoDbApplicationStoreResolver(IServiceProvider provider)
+    public OpenIddictMongoDbApplicationStoreResolver(IServiceProvider provider!!)
         => _provider = provider;
 
     /// <summary>

src/OpenIddict.MongoDb/Resolvers/OpenIddictMongoDbAuthorizationStoreResolver.cs

@@ -18,7 +18,7 @@ public class OpenIddictMongoDbAuthorizationStoreResolver : IOpenIddictAuthorizat
     private readonly ConcurrentDictionary<Type, Type> _cache = new ConcurrentDictionary<Type, Type>();
     private readonly IServiceProvider _provider;
 
-    public OpenIddictMongoDbAuthorizationStoreResolver(IServiceProvider provider)
+    public OpenIddictMongoDbAuthorizationStoreResolver(IServiceProvider provider!!)
         => _provider = provider;
 
     /// <summary>

src/OpenIddict.MongoDb/Resolvers/OpenIddictMongoDbScopeStoreResolver.cs

@@ -18,7 +18,7 @@ public class OpenIddictMongoDbScopeStoreResolver : IOpenIddictScopeStoreResolver
     private readonly ConcurrentDictionary<Type, Type> _cache = new ConcurrentDictionary<Type, Type>();
     private readonly IServiceProvider _provider;
 
-    public OpenIddictMongoDbScopeStoreResolver(IServiceProvider provider)
+    public OpenIddictMongoDbScopeStoreResolver(IServiceProvider provider!!)
         => _provider = provider;
 
     /// <summary>

src/OpenIddict.MongoDb/Resolvers/OpenIddictMongoDbTokenStoreResolver.cs

@@ -18,7 +18,7 @@ public class OpenIddictMongoDbTokenStoreResolver : IOpenIddictTokenStoreResolver
     private readonly ConcurrentDictionary<Type, Type> _cache = new ConcurrentDictionary<Type, Type>();
     private readonly IServiceProvider _provider;
 
-    public OpenIddictMongoDbTokenStoreResolver(IServiceProvider provider)
+    public OpenIddictMongoDbTokenStoreResolver(IServiceProvider provider!!)
         => _provider = provider;
 
     /// <summary>

src/OpenIddict.MongoDb/Stores/OpenIddictMongoDbApplicationStore.cs

@@ -23,8 +23,8 @@ public class OpenIddictMongoDbApplicationStore<TApplication> : IOpenIddictApplic
     where TApplication : OpenIddictMongoDbApplication
 {
     public OpenIddictMongoDbApplicationStore(
-        IOpenIddictMongoDbContext context,
-        IOptionsMonitor<OpenIddictMongoDbOptions> options)
+        IOpenIddictMongoDbContext context!!,
+        IOptionsMonitor<OpenIddictMongoDbOptions> options!!)
     {
         Context = context;
         Options = options;
@@ -51,13 +51,8 @@ public class OpenIddictMongoDbApplicationStore<TApplication> : IOpenIddictApplic
 
     /// <inheritdoc/>
     public virtual async ValueTask<long> CountAsync<TResult>(
-        Func<IQueryable<TApplication>, IQueryable<TResult>> query, CancellationToken cancellationToken)
+        Func<IQueryable<TApplication>, IQueryable<TResult>> query!!, CancellationToken cancellationToken)
     {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
         var database = await Context.GetDatabaseAsync(cancellationToken);
         var collection = database.GetCollection<TApplication>(Options.CurrentValue.ApplicationsCollectionName);
 
@@ -65,13 +60,8 @@ public class OpenIddictMongoDbApplicationStore<TApplication> : IOpenIddictApplic
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask CreateAsync(TApplication application, CancellationToken cancellationToken)
+    public virtual async ValueTask CreateAsync(TApplication application!!, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         var database = await Context.GetDatabaseAsync(cancellationToken);
         var collection = database.GetCollection<TApplication>(Options.CurrentValue.ApplicationsCollectionName);
 
@@ -79,13 +69,8 @@ public class OpenIddictMongoDbApplicationStore<TApplication> : IOpenIddictApplic
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask DeleteAsync(TApplication application, CancellationToken cancellationToken)
+    public virtual async ValueTask DeleteAsync(TApplication application!!, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         var database = await Context.GetDatabaseAsync(cancellationToken);
         var collection = database.GetCollection<TApplication>(Options.CurrentValue.ApplicationsCollectionName);
 
@@ -135,8 +120,7 @@ public class OpenIddictMongoDbApplicationStore<TApplication> : IOpenIddictApplic
     }
 
     /// <inheritdoc/>
-    public virtual IAsyncEnumerable<TApplication> FindByPostLogoutRedirectUriAsync(
-        string address, CancellationToken cancellationToken)
+    public virtual IAsyncEnumerable<TApplication> FindByPostLogoutRedirectUriAsync(string address, CancellationToken cancellationToken)
     {
         if (string.IsNullOrEmpty(address))
         {
@@ -159,8 +143,7 @@ public class OpenIddictMongoDbApplicationStore<TApplication> : IOpenIddictApplic
     }
 
     /// <inheritdoc/>
-    public virtual IAsyncEnumerable<TApplication> FindByRedirectUriAsync(
-        string address, CancellationToken cancellationToken)
+    public virtual IAsyncEnumerable<TApplication> FindByRedirectUriAsync(string address, CancellationToken cancellationToken)
     {
         if (string.IsNullOrEmpty(address))
         {
@@ -184,14 +167,9 @@ public class OpenIddictMongoDbApplicationStore<TApplication> : IOpenIddictApplic
 
     /// <inheritdoc/>
     public virtual async ValueTask<TResult?> GetAsync<TState, TResult>(
-        Func<IQueryable<TApplication>, TState, IQueryable<TResult>> query,
+        Func<IQueryable<TApplication>, TState, IQueryable<TResult>> query!!,
         TState state, CancellationToken cancellationToken)
     {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
         var database = await Context.GetDatabaseAsync(cancellationToken);
         var collection = database.GetCollection<TApplication>(Options.CurrentValue.ApplicationsCollectionName);
 
@@ -199,132 +177,47 @@ public class OpenIddictMongoDbApplicationStore<TApplication> : IOpenIddictApplic
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetClientIdAsync(TApplication application, CancellationToken cancellationToken)
-    {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        return new ValueTask<string?>(application.ClientId);
-    }
+    public virtual ValueTask<string?> GetClientIdAsync(TApplication application!!, CancellationToken cancellationToken)
+        => new(application.ClientId);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetClientSecretAsync(TApplication application, CancellationToken cancellationToken)
-    {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        return new ValueTask<string?>(application.ClientSecret);
-    }
+    public virtual ValueTask<string?> GetClientSecretAsync(TApplication application!!, CancellationToken cancellationToken)
+        => new(application.ClientSecret);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetClientTypeAsync(TApplication application, CancellationToken cancellationToken)
-    {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        return new ValueTask<string?>(application.Type);
-    }
+    public virtual ValueTask<string?> GetClientTypeAsync(TApplication application!!, CancellationToken cancellationToken)
+        => new(application.Type);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetConsentTypeAsync(TApplication application, CancellationToken cancellationToken)
-    {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        return new ValueTask<string?>(application.ConsentType);
-    }
+    public virtual ValueTask<string?> GetConsentTypeAsync(TApplication application!!, CancellationToken cancellationToken)
+        => new(application.ConsentType);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetDisplayNameAsync(TApplication application, CancellationToken cancellationToken)
-    {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        return new ValueTask<string?>(application.DisplayName);
-    }
+    public virtual ValueTask<string?> GetDisplayNameAsync(TApplication application!!, CancellationToken cancellationToken)
+        => new(application.DisplayName);
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableDictionary<CultureInfo, string>> GetDisplayNamesAsync(TApplication application, CancellationToken cancellationToken)
-    {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        if (application.DisplayNames is null || application.DisplayNames.Count == 0)
-        {
-            return new ValueTask<ImmutableDictionary<CultureInfo, string>>(ImmutableDictionary.Create<CultureInfo, string>());
-        }
-
-        return new ValueTask<ImmutableDictionary<CultureInfo, string>>(application.DisplayNames.ToImmutableDictionary());
-    }
+    public virtual ValueTask<ImmutableDictionary<CultureInfo, string>> GetDisplayNamesAsync(TApplication application!!, CancellationToken cancellationToken)
+        => new(application.DisplayNames is { Count: > 0 } names ? names.ToImmutableDictionary() : ImmutableDictionary.Create<CultureInfo, string>());
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetIdAsync(TApplication application, CancellationToken cancellationToken)
-    {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        return new ValueTask<string?>(application.Id.ToString());
-    }
+    public virtual ValueTask<string?> GetIdAsync(TApplication application!!, CancellationToken cancellationToken)
+        => new(application.Id.ToString());
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableArray<string>> GetPermissionsAsync(
-        TApplication application, CancellationToken cancellationToken)
-    {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        if (application.Permissions is null || application.Permissions.Count == 0)
-        {
-            return new ValueTask<ImmutableArray<string>>(ImmutableArray.Create<string>());
-        }
-
-        return new ValueTask<ImmutableArray<string>>(application.Permissions.ToImmutableArray());
-    }
+    public virtual ValueTask<ImmutableArray<string>> GetPermissionsAsync(TApplication application!!, CancellationToken cancellationToken)
+        => new(application.Permissions is { Count: > 0 } permissions ? permissions.ToImmutableArray() : ImmutableArray.Create<string>());
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableArray<string>> GetPostLogoutRedirectUrisAsync(
-        TApplication application, CancellationToken cancellationToken)
-    {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        if (application.PostLogoutRedirectUris is null || application.PostLogoutRedirectUris.Count == 0)
-        {
-            return new ValueTask<ImmutableArray<string>>(ImmutableArray.Create<string>());
-        }
-
-        return new ValueTask<ImmutableArray<string>>(application.PostLogoutRedirectUris.ToImmutableArray());
-    }
+    public virtual ValueTask<ImmutableArray<string>> GetPostLogoutRedirectUrisAsync(TApplication application!!, CancellationToken cancellationToken)
+        => new(application.PostLogoutRedirectUris is { Count: > 0 } addresses ? addresses.ToImmutableArray() : ImmutableArray.Create<string>());
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableDictionary<string, JsonElement>> GetPropertiesAsync(TApplication application, CancellationToken cancellationToken)
+    public virtual ValueTask<ImmutableDictionary<string, JsonElement>> GetPropertiesAsync(TApplication application!!, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         if (application.Properties is null)
         {
-            return new ValueTask<ImmutableDictionary<string, JsonElement>>(ImmutableDictionary.Create<string, JsonElement>());
+            return new(ImmutableDictionary.Create<string, JsonElement>());
         }
 
         using var document = JsonDocument.Parse(application.Properties.ToJson());
@@ -335,53 +228,28 @@ public class OpenIddictMongoDbApplicationStore<TApplication> : IOpenIddictApplic
             builder[property.Name] = property.Value.Clone();
         }
 
-        return new ValueTask<ImmutableDictionary<string, JsonElement>>(builder.ToImmutable());
+        return new(builder.ToImmutable());
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableArray<string>> GetRedirectUrisAsync(
-        TApplication application, CancellationToken cancellationToken)
-    {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        if (application.RedirectUris is null || application.RedirectUris.Count == 0)
-        {
-            return new ValueTask<ImmutableArray<string>>(ImmutableArray.Create<string>());
-        }
-
-        return new ValueTask<ImmutableArray<string>>(application.RedirectUris.ToImmutableArray());
-    }
+    public virtual ValueTask<ImmutableArray<string>> GetRedirectUrisAsync(TApplication application!!, CancellationToken cancellationToken)
+        => new(application.RedirectUris is { Count: > 0 } addresses ? addresses.ToImmutableArray() : ImmutableArray.Create<string>());
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableArray<string>> GetRequirementsAsync(TApplication application, CancellationToken cancellationToken)
-    {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        if (application.Requirements is null || application.Requirements.Count == 0)
-        {
-            return new ValueTask<ImmutableArray<string>>(ImmutableArray.Create<string>());
-        }
-
-        return new ValueTask<ImmutableArray<string>>(application.Requirements.ToImmutableArray());
-    }
+    public virtual ValueTask<ImmutableArray<string>> GetRequirementsAsync(TApplication application!!, CancellationToken cancellationToken)
+        => new(application.Requirements is { Count: > 0 } requirements ? requirements.ToImmutableArray() : ImmutableArray.Create<string>());
 
     /// <inheritdoc/>
     public virtual ValueTask<TApplication> InstantiateAsync(CancellationToken cancellationToken)
     {
         try
         {
-            return new ValueTask<TApplication>(Activator.CreateInstance<TApplication>());
+            return new(Activator.CreateInstance<TApplication>());
         }
 
         catch (MemberAccessException exception)
         {
-            return new ValueTask<TApplication>(Task.FromException<TApplication>(
+            return new(Task.FromException<TApplication>(
                 new InvalidOperationException(SR.GetResourceString(SR.ID0240), exception)));
         }
     }
@@ -413,14 +281,9 @@ public class OpenIddictMongoDbApplicationStore<TApplication> : IOpenIddictApplic
 
     /// <inheritdoc/>
     public virtual IAsyncEnumerable<TResult> ListAsync<TState, TResult>(
-        Func<IQueryable<TApplication>, TState, IQueryable<TResult>> query,
+        Func<IQueryable<TApplication>, TState, IQueryable<TResult>> query!!,
         TState state, CancellationToken cancellationToken)
     {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
         return ExecuteAsync(cancellationToken);
 
         async IAsyncEnumerable<TResult> ExecuteAsync([EnumeratorCancellation] CancellationToken cancellationToken)
@@ -436,97 +299,62 @@ public class OpenIddictMongoDbApplicationStore<TApplication> : IOpenIddictApplic
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetClientIdAsync(TApplication application,
+    public virtual ValueTask SetClientIdAsync(TApplication application!!,
         string? identifier, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         application.ClientId = identifier;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetClientSecretAsync(TApplication application,
+    public virtual ValueTask SetClientSecretAsync(TApplication application!!,
         string? secret, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         application.ClientSecret = secret;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetClientTypeAsync(TApplication application,
+    public virtual ValueTask SetClientTypeAsync(TApplication application!!,
         string? type, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         application.Type = type;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetConsentTypeAsync(TApplication application,
+    public virtual ValueTask SetConsentTypeAsync(TApplication application!!,
         string? type, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         application.ConsentType = type;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetDisplayNameAsync(TApplication application,
+    public virtual ValueTask SetDisplayNameAsync(TApplication application!!,
         string? name, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         application.DisplayName = name;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetDisplayNamesAsync(TApplication application,
+    public virtual ValueTask SetDisplayNamesAsync(TApplication application!!,
         ImmutableDictionary<CultureInfo, string> names, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         application.DisplayNames = names;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetPermissionsAsync(TApplication application, ImmutableArray<string> permissions, CancellationToken cancellationToken)
+    public virtual ValueTask SetPermissionsAsync(TApplication application!!, ImmutableArray<string> permissions, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         if (permissions.IsDefaultOrEmpty)
         {
             application.Permissions = ImmutableList.Create<string>();
@@ -540,14 +368,9 @@ public class OpenIddictMongoDbApplicationStore<TApplication> : IOpenIddictApplic
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetPostLogoutRedirectUrisAsync(TApplication application,
+    public virtual ValueTask SetPostLogoutRedirectUrisAsync(TApplication application!!,
         ImmutableArray<string> addresses, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         if (addresses.IsDefaultOrEmpty)
         {
             application.PostLogoutRedirectUris = ImmutableList.Create<string>();
@@ -561,15 +384,10 @@ public class OpenIddictMongoDbApplicationStore<TApplication> : IOpenIddictApplic
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetPropertiesAsync(TApplication application,
+    public virtual ValueTask SetPropertiesAsync(TApplication application!!,
         ImmutableDictionary<string, JsonElement> properties, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
-        if (properties is null || properties.IsEmpty)
+        if (properties is not { IsEmpty: false })
         {
             application.Properties = null;
 
@@ -600,14 +418,9 @@ public class OpenIddictMongoDbApplicationStore<TApplication> : IOpenIddictApplic
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetRedirectUrisAsync(TApplication application,
+    public virtual ValueTask SetRedirectUrisAsync(TApplication application!!,
         ImmutableArray<string> addresses, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         if (addresses.IsDefaultOrEmpty)
         {
             application.RedirectUris = ImmutableList.Create<string>();
@@ -621,14 +434,9 @@ public class OpenIddictMongoDbApplicationStore<TApplication> : IOpenIddictApplic
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetRequirementsAsync(TApplication application,
+    public virtual ValueTask SetRequirementsAsync(TApplication application!!,
         ImmutableArray<string> requirements, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         if (requirements.IsDefaultOrEmpty)
         {
             application.Requirements = ImmutableList.Create<string>();
@@ -642,13 +450,8 @@ public class OpenIddictMongoDbApplicationStore<TApplication> : IOpenIddictApplic
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask UpdateAsync(TApplication application, CancellationToken cancellationToken)
+    public virtual async ValueTask UpdateAsync(TApplication application!!, CancellationToken cancellationToken)
     {
-        if (application is null)
-        {
-            throw new ArgumentNullException(nameof(application));
-        }
-
         // Generate a new concurrency token and attach it
         // to the application before persisting the changes.
         var timestamp = application.ConcurrencyToken;

src/OpenIddict.MongoDb/Stores/OpenIddictMongoDbAuthorizationStore.cs

@@ -22,8 +22,8 @@ public class OpenIddictMongoDbAuthorizationStore<TAuthorization> : IOpenIddictAu
     where TAuthorization : OpenIddictMongoDbAuthorization
 {
     public OpenIddictMongoDbAuthorizationStore(
-        IOpenIddictMongoDbContext context,
-        IOptionsMonitor<OpenIddictMongoDbOptions> options)
+        IOpenIddictMongoDbContext context!!,
+        IOptionsMonitor<OpenIddictMongoDbOptions> options!!)
     {
         Context = context;
         Options = options;
@@ -50,13 +50,8 @@ public class OpenIddictMongoDbAuthorizationStore<TAuthorization> : IOpenIddictAu
 
     /// <inheritdoc/>
     public virtual async ValueTask<long> CountAsync<TResult>(
-        Func<IQueryable<TAuthorization>, IQueryable<TResult>> query, CancellationToken cancellationToken)
+        Func<IQueryable<TAuthorization>, IQueryable<TResult>> query!!, CancellationToken cancellationToken)
     {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
         var database = await Context.GetDatabaseAsync(cancellationToken);
         var collection = database.GetCollection<TAuthorization>(Options.CurrentValue.AuthorizationsCollectionName);
 
@@ -64,13 +59,8 @@ public class OpenIddictMongoDbAuthorizationStore<TAuthorization> : IOpenIddictAu
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask CreateAsync(TAuthorization authorization, CancellationToken cancellationToken)
+    public virtual async ValueTask CreateAsync(TAuthorization authorization!!, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         var database = await Context.GetDatabaseAsync(cancellationToken);
         var collection = database.GetCollection<TAuthorization>(Options.CurrentValue.AuthorizationsCollectionName);
 
@@ -78,13 +68,8 @@ public class OpenIddictMongoDbAuthorizationStore<TAuthorization> : IOpenIddictAu
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask DeleteAsync(TAuthorization authorization, CancellationToken cancellationToken)
+    public virtual async ValueTask DeleteAsync(TAuthorization authorization!!, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         var database = await Context.GetDatabaseAsync(cancellationToken);
         var collection = database.GetCollection<TAuthorization>(Options.CurrentValue.AuthorizationsCollectionName);
 
@@ -321,31 +306,21 @@ public class OpenIddictMongoDbAuthorizationStore<TAuthorization> : IOpenIddictAu
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetApplicationIdAsync(TAuthorization authorization, CancellationToken cancellationToken)
+    public virtual ValueTask<string?> GetApplicationIdAsync(TAuthorization authorization!!, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         if (authorization.ApplicationId == ObjectId.Empty)
         {
-            return new ValueTask<string?>(result: null);
+            return new(result: null);
         }
 
-        return new ValueTask<string?>(authorization.ApplicationId.ToString());
+        return new(authorization.ApplicationId.ToString());
     }
 
     /// <inheritdoc/>
     public virtual async ValueTask<TResult?> GetAsync<TState, TResult>(
-        Func<IQueryable<TAuthorization>, TState, IQueryable<TResult>> query,
+        Func<IQueryable<TAuthorization>, TState, IQueryable<TResult>> query!!,
         TState state, CancellationToken cancellationToken)
     {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
         var database = await Context.GetDatabaseAsync(cancellationToken);
         var collection = database.GetCollection<TAuthorization>(Options.CurrentValue.AuthorizationsCollectionName);
 
@@ -353,43 +328,19 @@ public class OpenIddictMongoDbAuthorizationStore<TAuthorization> : IOpenIddictAu
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<DateTimeOffset?> GetCreationDateAsync(TAuthorization authorization, CancellationToken cancellationToken)
-    {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
-        if (authorization.CreationDate is null)
-        {
-            return new ValueTask<DateTimeOffset?>(result: null);
-        }
-
-        return new ValueTask<DateTimeOffset?>(DateTime.SpecifyKind(authorization.CreationDate.Value, DateTimeKind.Utc));
-    }
+    public virtual ValueTask<DateTimeOffset?> GetCreationDateAsync(TAuthorization authorization!!, CancellationToken cancellationToken)
+        => new(authorization.CreationDate is DateTime date ? DateTime.SpecifyKind(date, DateTimeKind.Utc) : null);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetIdAsync(TAuthorization authorization, CancellationToken cancellationToken)
-    {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
-        return new ValueTask<string?>(authorization.Id.ToString());
-    }
+    public virtual ValueTask<string?> GetIdAsync(TAuthorization authorization!!, CancellationToken cancellationToken)
+        => new(authorization.Id.ToString());
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableDictionary<string, JsonElement>> GetPropertiesAsync(TAuthorization authorization, CancellationToken cancellationToken)
+    public virtual ValueTask<ImmutableDictionary<string, JsonElement>> GetPropertiesAsync(TAuthorization authorization!!, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         if (authorization.Properties is null)
         {
-            return new ValueTask<ImmutableDictionary<string, JsonElement>>(ImmutableDictionary.Create<string, JsonElement>());
+            return new(ImmutableDictionary.Create<string, JsonElement>());
         }
 
         using var document = JsonDocument.Parse(authorization.Properties.ToJson());
@@ -400,69 +351,36 @@ public class OpenIddictMongoDbAuthorizationStore<TAuthorization> : IOpenIddictAu
             builder[property.Name] = property.Value.Clone();
         }
 
-        return new ValueTask<ImmutableDictionary<string, JsonElement>>(builder.ToImmutable());
+        return new(builder.ToImmutable());
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableArray<string>> GetScopesAsync(TAuthorization authorization, CancellationToken cancellationToken)
-    {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
-        if (authorization.Scopes is null || authorization.Scopes.Count == 0)
-        {
-            return new ValueTask<ImmutableArray<string>>(ImmutableArray.Create<string>());
-        }
-
-        return new ValueTask<ImmutableArray<string>>(authorization.Scopes.ToImmutableArray());
-    }
+    public virtual ValueTask<ImmutableArray<string>> GetScopesAsync(TAuthorization authorization!!, CancellationToken cancellationToken)
+        => new(authorization.Scopes is { Count: > 0 } scopes ? scopes.ToImmutableArray() : ImmutableArray.Create<string>());
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetStatusAsync(TAuthorization authorization, CancellationToken cancellationToken)
-    {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
-        return new ValueTask<string?>(authorization.Status);
-    }
+    public virtual ValueTask<string?> GetStatusAsync(TAuthorization authorization!!, CancellationToken cancellationToken)
+        => new(authorization.Status);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetSubjectAsync(TAuthorization authorization, CancellationToken cancellationToken)
-    {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
-        return new ValueTask<string?>(authorization.Subject);
-    }
+    public virtual ValueTask<string?> GetSubjectAsync(TAuthorization authorization!!, CancellationToken cancellationToken)
+        => new(authorization.Subject);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetTypeAsync(TAuthorization authorization, CancellationToken cancellationToken)
-    {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
-        return new ValueTask<string?>(authorization.Type);
-    }
+    public virtual ValueTask<string?> GetTypeAsync(TAuthorization authorization!!, CancellationToken cancellationToken)
+        => new(authorization.Type);
 
     /// <inheritdoc/>
     public virtual ValueTask<TAuthorization> InstantiateAsync(CancellationToken cancellationToken)
     {
         try
         {
-            return new ValueTask<TAuthorization>(Activator.CreateInstance<TAuthorization>());
+            return new(Activator.CreateInstance<TAuthorization>());
         }
 
         catch (MemberAccessException exception)
         {
-            return new ValueTask<TAuthorization>(Task.FromException<TAuthorization>(
+            return new(Task.FromException<TAuthorization>(
                 new InvalidOperationException(SR.GetResourceString(SR.ID0242), exception)));
         }
     }
@@ -494,14 +412,9 @@ public class OpenIddictMongoDbAuthorizationStore<TAuthorization> : IOpenIddictAu
 
     /// <inheritdoc/>
     public virtual IAsyncEnumerable<TResult> ListAsync<TState, TResult>(
-        Func<IQueryable<TAuthorization>, TState, IQueryable<TResult>> query,
+        Func<IQueryable<TAuthorization>, TState, IQueryable<TResult>> query!!,
         TState state, CancellationToken cancellationToken)
     {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
         return ExecuteAsync(cancellationToken);
 
         async IAsyncEnumerable<TResult> ExecuteAsync([EnumeratorCancellation] CancellationToken cancellationToken)
@@ -567,14 +480,9 @@ public class OpenIddictMongoDbAuthorizationStore<TAuthorization> : IOpenIddictAu
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetApplicationIdAsync(TAuthorization authorization,
+    public virtual ValueTask SetApplicationIdAsync(TAuthorization authorization!!,
         string? identifier, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         if (!string.IsNullOrEmpty(identifier))
         {
             authorization.ApplicationId = ObjectId.Parse(identifier);
@@ -589,29 +497,19 @@ public class OpenIddictMongoDbAuthorizationStore<TAuthorization> : IOpenIddictAu
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetCreationDateAsync(TAuthorization authorization,
+    public virtual ValueTask SetCreationDateAsync(TAuthorization authorization!!,
         DateTimeOffset? date, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         authorization.CreationDate = date?.UtcDateTime;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetPropertiesAsync(TAuthorization authorization,
+    public virtual ValueTask SetPropertiesAsync(TAuthorization authorization!!,
         ImmutableDictionary<string, JsonElement> properties, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
-        if (properties is null || properties.IsEmpty)
+        if (properties is not { IsEmpty: false })
         {
             authorization.Properties = null;
 
@@ -642,14 +540,9 @@ public class OpenIddictMongoDbAuthorizationStore<TAuthorization> : IOpenIddictAu
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetScopesAsync(TAuthorization authorization,
+    public virtual ValueTask SetScopesAsync(TAuthorization authorization!!,
         ImmutableArray<string> scopes, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         if (scopes.IsDefaultOrEmpty)
         {
             authorization.Scopes = ImmutableList.Create<string>();
@@ -663,52 +556,32 @@ public class OpenIddictMongoDbAuthorizationStore<TAuthorization> : IOpenIddictAu
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetStatusAsync(TAuthorization authorization, string? status, CancellationToken cancellationToken)
+    public virtual ValueTask SetStatusAsync(TAuthorization authorization!!, string? status, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         authorization.Status = status;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetSubjectAsync(TAuthorization authorization, string? subject, CancellationToken cancellationToken)
+    public virtual ValueTask SetSubjectAsync(TAuthorization authorization!!, string? subject, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         authorization.Subject = subject;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetTypeAsync(TAuthorization authorization, string? type, CancellationToken cancellationToken)
+    public virtual ValueTask SetTypeAsync(TAuthorization authorization!!, string? type, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         authorization.Type = type;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask UpdateAsync(TAuthorization authorization, CancellationToken cancellationToken)
+    public virtual async ValueTask UpdateAsync(TAuthorization authorization!!, CancellationToken cancellationToken)
     {
-        if (authorization is null)
-        {
-            throw new ArgumentNullException(nameof(authorization));
-        }
-
         // Generate a new concurrency token and attach it
         // to the authorization before persisting the changes.
         var timestamp = authorization.ConcurrencyToken;

src/OpenIddict.MongoDb/Stores/OpenIddictMongoDbScopeStore.cs

@@ -23,8 +23,8 @@ public class OpenIddictMongoDbScopeStore<TScope> : IOpenIddictScopeStore<TScope>
     where TScope : OpenIddictMongoDbScope
 {
     public OpenIddictMongoDbScopeStore(
-        IOpenIddictMongoDbContext context,
-        IOptionsMonitor<OpenIddictMongoDbOptions> options)
+        IOpenIddictMongoDbContext context!!,
+        IOptionsMonitor<OpenIddictMongoDbOptions> options!!)
     {
         Context = context;
         Options = options;
@@ -51,13 +51,8 @@ public class OpenIddictMongoDbScopeStore<TScope> : IOpenIddictScopeStore<TScope>
 
     /// <inheritdoc/>
     public virtual async ValueTask<long> CountAsync<TResult>(
-        Func<IQueryable<TScope>, IQueryable<TResult>> query, CancellationToken cancellationToken)
+        Func<IQueryable<TScope>, IQueryable<TResult>> query!!, CancellationToken cancellationToken)
     {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
         var database = await Context.GetDatabaseAsync(cancellationToken);
         var collection = database.GetCollection<TScope>(Options.CurrentValue.ScopesCollectionName);
 
@@ -65,13 +60,8 @@ public class OpenIddictMongoDbScopeStore<TScope> : IOpenIddictScopeStore<TScope>
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask CreateAsync(TScope scope, CancellationToken cancellationToken)
+    public virtual async ValueTask CreateAsync(TScope scope!!, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         var database = await Context.GetDatabaseAsync(cancellationToken);
         var collection = database.GetCollection<TScope>(Options.CurrentValue.ScopesCollectionName);
 
@@ -79,13 +69,8 @@ public class OpenIddictMongoDbScopeStore<TScope> : IOpenIddictScopeStore<TScope>
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask DeleteAsync(TScope scope, CancellationToken cancellationToken)
+    public virtual async ValueTask DeleteAsync(TScope scope!!, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         var database = await Context.GetDatabaseAsync(cancellationToken);
         var collection = database.GetCollection<TScope>(Options.CurrentValue.ScopesCollectionName);
 
@@ -128,7 +113,7 @@ public class OpenIddictMongoDbScopeStore<TScope> : IOpenIddictScopeStore<TScope>
     /// <inheritdoc/>
     public virtual IAsyncEnumerable<TScope> FindByNamesAsync(ImmutableArray<string> names, CancellationToken cancellationToken)
     {
-        if (names.Any(name => string.IsNullOrEmpty(name)))
+        if (names.Any(string.IsNullOrEmpty))
         {
             throw new ArgumentException(SR.GetResourceString(SR.ID0203), nameof(names));
         }
@@ -173,14 +158,9 @@ public class OpenIddictMongoDbScopeStore<TScope> : IOpenIddictScopeStore<TScope>
 
     /// <inheritdoc/>
     public virtual async ValueTask<TResult?> GetAsync<TState, TResult>(
-        Func<IQueryable<TScope>, TState, IQueryable<TResult>> query,
+        Func<IQueryable<TScope>, TState, IQueryable<TResult>> query!!,
         TState state, CancellationToken cancellationToken)
     {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
         var database = await Context.GetDatabaseAsync(cancellationToken);
         var collection = database.GetCollection<TScope>(Options.CurrentValue.ScopesCollectionName);
 
@@ -188,92 +168,35 @@ public class OpenIddictMongoDbScopeStore<TScope> : IOpenIddictScopeStore<TScope>
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetDescriptionAsync(TScope scope, CancellationToken cancellationToken)
-    {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
-        return new ValueTask<string?>(scope.Description);
-    }
+    public virtual ValueTask<string?> GetDescriptionAsync(TScope scope!!, CancellationToken cancellationToken)
+        => new(scope.Description);
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableDictionary<CultureInfo, string>> GetDescriptionsAsync(TScope scope, CancellationToken cancellationToken)
-    {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
-        if (scope.Descriptions is null || scope.Descriptions.Count == 0)
-        {
-            return new ValueTask<ImmutableDictionary<CultureInfo, string>>(ImmutableDictionary.Create<CultureInfo, string>());
-        }
-
-        return new ValueTask<ImmutableDictionary<CultureInfo, string>>(scope.Descriptions.ToImmutableDictionary());
-    }
+    public virtual ValueTask<ImmutableDictionary<CultureInfo, string>> GetDescriptionsAsync(TScope scope!!, CancellationToken cancellationToken)
+        => new(scope.Descriptions is { Count: > 0 } descriptions ? descriptions.ToImmutableDictionary() : ImmutableDictionary.Create<CultureInfo, string>());
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetDisplayNameAsync(TScope scope, CancellationToken cancellationToken)
-    {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
-        return new ValueTask<string?>(scope.DisplayName);
-    }
+    public virtual ValueTask<string?> GetDisplayNameAsync(TScope scope!!, CancellationToken cancellationToken)
+        => new(scope.DisplayName);
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableDictionary<CultureInfo, string>> GetDisplayNamesAsync(TScope scope, CancellationToken cancellationToken)
-    {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
-        if (scope.DisplayNames is null || scope.DisplayNames.Count == 0)
-        {
-            return new ValueTask<ImmutableDictionary<CultureInfo, string>>(ImmutableDictionary.Create<CultureInfo, string>());
-        }
-
-        return new ValueTask<ImmutableDictionary<CultureInfo, string>>(scope.DisplayNames.ToImmutableDictionary());
-    }
+    public virtual ValueTask<ImmutableDictionary<CultureInfo, string>> GetDisplayNamesAsync(TScope scope!!, CancellationToken cancellationToken)
+        => new(scope.DisplayNames is { Count: > 0 } names ? names.ToImmutableDictionary() : ImmutableDictionary.Create<CultureInfo, string>());
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetIdAsync(TScope scope, CancellationToken cancellationToken)
-    {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
-        return new ValueTask<string?>(scope.Id.ToString());
-    }
+    public virtual ValueTask<string?> GetIdAsync(TScope scope!!, CancellationToken cancellationToken)
+        => new(scope.Id.ToString());
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetNameAsync(TScope scope, CancellationToken cancellationToken)
-    {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
-        return new ValueTask<string?>(scope.Name);
-    }
+    public virtual ValueTask<string?> GetNameAsync(TScope scope!!, CancellationToken cancellationToken)
+        => new(scope.Name);
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableDictionary<string, JsonElement>> GetPropertiesAsync(TScope scope, CancellationToken cancellationToken)
+    public virtual ValueTask<ImmutableDictionary<string, JsonElement>> GetPropertiesAsync(TScope scope!!, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         if (scope.Properties is null)
         {
-            return new ValueTask<ImmutableDictionary<string, JsonElement>>(ImmutableDictionary.Create<string, JsonElement>());
+            return new(ImmutableDictionary.Create<string, JsonElement>());
         }
 
         using var document = JsonDocument.Parse(scope.Properties.ToJson());
@@ -284,36 +207,24 @@ public class OpenIddictMongoDbScopeStore<TScope> : IOpenIddictScopeStore<TScope>
             builder[property.Name] = property.Value.Clone();
         }
 
-        return new ValueTask<ImmutableDictionary<string, JsonElement>>(builder.ToImmutable());
+        return new(builder.ToImmutable());
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableArray<string>> GetResourcesAsync(TScope scope, CancellationToken cancellationToken)
-    {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
-        if (scope.Resources is null || scope.Resources.Count == 0)
-        {
-            return new ValueTask<ImmutableArray<string>>(ImmutableArray.Create<string>());
-        }
-
-        return new ValueTask<ImmutableArray<string>>(scope.Resources.ToImmutableArray());
-    }
+    public virtual ValueTask<ImmutableArray<string>> GetResourcesAsync(TScope scope!!, CancellationToken cancellationToken)
+        => new(scope.Resources is { Count: > 0 } resources ? resources.ToImmutableArray() : ImmutableArray.Create<string>());
 
     /// <inheritdoc/>
     public virtual ValueTask<TScope> InstantiateAsync(CancellationToken cancellationToken)
     {
         try
         {
-            return new ValueTask<TScope>(Activator.CreateInstance<TScope>());
+            return new(Activator.CreateInstance<TScope>());
         }
 
         catch (MemberAccessException exception)
         {
-            return new ValueTask<TScope>(Task.FromException<TScope>(
+            return new(Task.FromException<TScope>(
                 new InvalidOperationException(SR.GetResourceString(SR.ID0246), exception)));
         }
     }
@@ -345,14 +256,9 @@ public class OpenIddictMongoDbScopeStore<TScope> : IOpenIddictScopeStore<TScope>
 
     /// <inheritdoc/>
     public virtual IAsyncEnumerable<TResult> ListAsync<TState, TResult>(
-        Func<IQueryable<TScope>, TState, IQueryable<TResult>> query,
+        Func<IQueryable<TScope>, TState, IQueryable<TResult>> query!!,
         TState state, CancellationToken cancellationToken)
     {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
         return ExecuteAsync(cancellationToken);
 
         async IAsyncEnumerable<TResult> ExecuteAsync([EnumeratorCancellation] CancellationToken cancellationToken)
@@ -368,82 +274,52 @@ public class OpenIddictMongoDbScopeStore<TScope> : IOpenIddictScopeStore<TScope>
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetDescriptionAsync(TScope scope, string? description, CancellationToken cancellationToken)
+    public virtual ValueTask SetDescriptionAsync(TScope scope!!, string? description, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         scope.Description = description;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetDescriptionsAsync(TScope scope,
+    public virtual ValueTask SetDescriptionsAsync(TScope scope!!,
         ImmutableDictionary<CultureInfo, string> descriptions, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         scope.Descriptions = descriptions;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetDisplayNamesAsync(TScope scope,
+    public virtual ValueTask SetDisplayNamesAsync(TScope scope!!,
         ImmutableDictionary<CultureInfo, string> names, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         scope.DisplayNames = names;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetDisplayNameAsync(TScope scope, string? name, CancellationToken cancellationToken)
+    public virtual ValueTask SetDisplayNameAsync(TScope scope!!, string? name, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         scope.DisplayName = name;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetNameAsync(TScope scope, string? name, CancellationToken cancellationToken)
+    public virtual ValueTask SetNameAsync(TScope scope!!, string? name, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         scope.Name = name;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetPropertiesAsync(TScope scope,
+    public virtual ValueTask SetPropertiesAsync(TScope scope!!,
         ImmutableDictionary<string, JsonElement> properties, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
-        if (properties is null || properties.IsEmpty)
+        if (properties is not { IsEmpty: false })
         {
             scope.Properties = null;
 
@@ -474,13 +350,8 @@ public class OpenIddictMongoDbScopeStore<TScope> : IOpenIddictScopeStore<TScope>
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetResourcesAsync(TScope scope, ImmutableArray<string> resources, CancellationToken cancellationToken)
+    public virtual ValueTask SetResourcesAsync(TScope scope!!, ImmutableArray<string> resources, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         if (resources.IsDefaultOrEmpty)
         {
             scope.Resources = ImmutableList.Create<string>();
@@ -494,13 +365,8 @@ public class OpenIddictMongoDbScopeStore<TScope> : IOpenIddictScopeStore<TScope>
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask UpdateAsync(TScope scope, CancellationToken cancellationToken)
+    public virtual async ValueTask UpdateAsync(TScope scope!!, CancellationToken cancellationToken)
     {
-        if (scope is null)
-        {
-            throw new ArgumentNullException(nameof(scope));
-        }
-
         // Generate a new concurrency token and attach it
         // to the scope before persisting the changes.
         var timestamp = scope.ConcurrencyToken;

src/OpenIddict.MongoDb/Stores/OpenIddictMongoDbTokenStore.cs

@@ -22,8 +22,8 @@ public class OpenIddictMongoDbTokenStore<TToken> : IOpenIddictTokenStore<TToken>
     where TToken : OpenIddictMongoDbToken
 {
     public OpenIddictMongoDbTokenStore(
-        IOpenIddictMongoDbContext context,
-        IOptionsMonitor<OpenIddictMongoDbOptions> options)
+        IOpenIddictMongoDbContext context!!,
+        IOptionsMonitor<OpenIddictMongoDbOptions> options!!)
     {
         Context = context;
         Options = options;
@@ -50,13 +50,8 @@ public class OpenIddictMongoDbTokenStore<TToken> : IOpenIddictTokenStore<TToken>
 
     /// <inheritdoc/>
     public virtual async ValueTask<long> CountAsync<TResult>(
-        Func<IQueryable<TToken>, IQueryable<TResult>> query, CancellationToken cancellationToken)
+        Func<IQueryable<TToken>, IQueryable<TResult>> query!!, CancellationToken cancellationToken)
     {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
         var database = await Context.GetDatabaseAsync(cancellationToken);
         var collection = database.GetCollection<TToken>(Options.CurrentValue.TokensCollectionName);
 
@@ -64,13 +59,8 @@ public class OpenIddictMongoDbTokenStore<TToken> : IOpenIddictTokenStore<TToken>
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask CreateAsync(TToken token, CancellationToken cancellationToken)
+    public virtual async ValueTask CreateAsync(TToken token!!, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         var database = await Context.GetDatabaseAsync(cancellationToken);
         var collection = database.GetCollection<TToken>(Options.CurrentValue.TokensCollectionName);
 
@@ -78,13 +68,8 @@ public class OpenIddictMongoDbTokenStore<TToken> : IOpenIddictTokenStore<TToken>
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask DeleteAsync(TToken token, CancellationToken cancellationToken)
+    public virtual async ValueTask DeleteAsync(TToken token!!, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         var database = await Context.GetDatabaseAsync(cancellationToken);
         var collection = database.GetCollection<TToken>(Options.CurrentValue.TokensCollectionName);
 
@@ -303,31 +288,21 @@ public class OpenIddictMongoDbTokenStore<TToken> : IOpenIddictTokenStore<TToken>
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetApplicationIdAsync(TToken token, CancellationToken cancellationToken)
+    public virtual ValueTask<string?> GetApplicationIdAsync(TToken token!!, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         if (token.ApplicationId == ObjectId.Empty)
         {
-            return new ValueTask<string?>(result: null);
+            return new(result: null);
         }
 
-        return new ValueTask<string?>(token.ApplicationId.ToString());
+        return new(token.ApplicationId.ToString());
     }
 
     /// <inheritdoc/>
     public virtual async ValueTask<TResult?> GetAsync<TState, TResult>(
-        Func<IQueryable<TToken>, TState, IQueryable<TResult>> query,
+        Func<IQueryable<TToken>, TState, IQueryable<TResult>> query!!,
         TState state, CancellationToken cancellationToken)
     {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
         var database = await Context.GetDatabaseAsync(cancellationToken);
         var collection = database.GetCollection<TToken>(Options.CurrentValue.TokensCollectionName);
 
@@ -335,86 +310,38 @@ public class OpenIddictMongoDbTokenStore<TToken> : IOpenIddictTokenStore<TToken>
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetAuthorizationIdAsync(TToken token, CancellationToken cancellationToken)
+    public virtual ValueTask<string?> GetAuthorizationIdAsync(TToken token!!, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         if (token.AuthorizationId == ObjectId.Empty)
         {
-            return new ValueTask<string?>(result: null);
+            return new(result: null);
         }
 
-        return new ValueTask<string?>(token.AuthorizationId.ToString());
+        return new(token.AuthorizationId.ToString());
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<DateTimeOffset?> GetCreationDateAsync(TToken token, CancellationToken cancellationToken)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        if (token.CreationDate is null)
-        {
-            return new ValueTask<DateTimeOffset?>(result: null);
-        }
-
-        return new ValueTask<DateTimeOffset?>(DateTime.SpecifyKind(token.CreationDate.Value, DateTimeKind.Utc));
-    }
+    public virtual ValueTask<DateTimeOffset?> GetCreationDateAsync(TToken token!!, CancellationToken cancellationToken)
+        => new(token.CreationDate is DateTime date ? DateTime.SpecifyKind(date, DateTimeKind.Utc) : null);
 
     /// <inheritdoc/>
-    public virtual ValueTask<DateTimeOffset?> GetExpirationDateAsync(TToken token, CancellationToken cancellationToken)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        if (token.ExpirationDate is null)
-        {
-            return new ValueTask<DateTimeOffset?>(result: null);
-        }
-
-        return new ValueTask<DateTimeOffset?>(DateTime.SpecifyKind(token.ExpirationDate.Value, DateTimeKind.Utc));
-    }
+    public virtual ValueTask<DateTimeOffset?> GetExpirationDateAsync(TToken token!!, CancellationToken cancellationToken)
+        => new(token.ExpirationDate is DateTime date ? DateTime.SpecifyKind(date, DateTimeKind.Utc) : null);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetIdAsync(TToken token, CancellationToken cancellationToken)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        return new ValueTask<string?>(token.Id.ToString());
-    }
+    public virtual ValueTask<string?> GetIdAsync(TToken token!!, CancellationToken cancellationToken)
+        => new(token.Id.ToString());
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetPayloadAsync(TToken token, CancellationToken cancellationToken)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        return new ValueTask<string?>(token.Payload);
-    }
+    public virtual ValueTask<string?> GetPayloadAsync(TToken token!!, CancellationToken cancellationToken)
+        => new(token.Payload);
 
     /// <inheritdoc/>
-    public virtual ValueTask<ImmutableDictionary<string, JsonElement>> GetPropertiesAsync(TToken token, CancellationToken cancellationToken)
+    public virtual ValueTask<ImmutableDictionary<string, JsonElement>> GetPropertiesAsync(TToken token!!, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         if (token.Properties is null)
         {
-            return new ValueTask<ImmutableDictionary<string, JsonElement>>(ImmutableDictionary.Create<string, JsonElement>());
+            return new(ImmutableDictionary.Create<string, JsonElement>());
         }
 
         using var document = JsonDocument.Parse(token.Properties.ToJson());
@@ -425,80 +352,40 @@ public class OpenIddictMongoDbTokenStore<TToken> : IOpenIddictTokenStore<TToken>
             builder[property.Name] = property.Value.Clone();
         }
 
-        return new ValueTask<ImmutableDictionary<string, JsonElement>>(builder.ToImmutable());
+        return new(builder.ToImmutable());
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask<DateTimeOffset?> GetRedemptionDateAsync(TToken token, CancellationToken cancellationToken)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        if (token.RedemptionDate is null)
-        {
-            return new ValueTask<DateTimeOffset?>(result: null);
-        }
-
-        return new ValueTask<DateTimeOffset?>(DateTime.SpecifyKind(token.RedemptionDate.Value, DateTimeKind.Utc));
-    }
+    public virtual ValueTask<DateTimeOffset?> GetRedemptionDateAsync(TToken token!!, CancellationToken cancellationToken)
+        => new(token.RedemptionDate is DateTime date ? DateTime.SpecifyKind(date, DateTimeKind.Utc) : null);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetReferenceIdAsync(TToken token, CancellationToken cancellationToken)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        return new ValueTask<string?>(token.ReferenceId);
-    }
+    public virtual ValueTask<string?> GetReferenceIdAsync(TToken token!!, CancellationToken cancellationToken)
+        => new(token.ReferenceId);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetStatusAsync(TToken token, CancellationToken cancellationToken)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        return new ValueTask<string?>(token.Status);
-    }
+    public virtual ValueTask<string?> GetStatusAsync(TToken token!!, CancellationToken cancellationToken)
+        => new(token.Status);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetSubjectAsync(TToken token, CancellationToken cancellationToken)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        return new ValueTask<string?>(token.Subject);
-    }
+    public virtual ValueTask<string?> GetSubjectAsync(TToken token!!, CancellationToken cancellationToken)
+        => new(token.Subject);
 
     /// <inheritdoc/>
-    public virtual ValueTask<string?> GetTypeAsync(TToken token, CancellationToken cancellationToken)
-    {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        return new ValueTask<string?>(token.Type);
-    }
+    public virtual ValueTask<string?> GetTypeAsync(TToken token!!, CancellationToken cancellationToken)
+        => new(token.Type);
 
     /// <inheritdoc/>
     public virtual ValueTask<TToken> InstantiateAsync(CancellationToken cancellationToken)
     {
         try
         {
-            return new ValueTask<TToken>(Activator.CreateInstance<TToken>());
+            return new(Activator.CreateInstance<TToken>());
         }
 
         catch (MemberAccessException exception)
         {
-            return new ValueTask<TToken>(Task.FromException<TToken>(
+            return new(Task.FromException<TToken>(
                 new InvalidOperationException(SR.GetResourceString(SR.ID0248), exception)));
         }
     }
@@ -530,14 +417,9 @@ public class OpenIddictMongoDbTokenStore<TToken> : IOpenIddictTokenStore<TToken>
 
     /// <inheritdoc/>
     public virtual IAsyncEnumerable<TResult> ListAsync<TState, TResult>(
-        Func<IQueryable<TToken>, TState, IQueryable<TResult>> query,
+        Func<IQueryable<TToken>, TState, IQueryable<TResult>> query!!,
         TState state, CancellationToken cancellationToken)
     {
-        if (query is null)
-        {
-            throw new ArgumentNullException(nameof(query));
-        }
-
         return ExecuteAsync(cancellationToken);
 
         async IAsyncEnumerable<TResult> ExecuteAsync([EnumeratorCancellation] CancellationToken cancellationToken)
@@ -604,13 +486,8 @@ public class OpenIddictMongoDbTokenStore<TToken> : IOpenIddictTokenStore<TToken>
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetApplicationIdAsync(TToken token, string? identifier, CancellationToken cancellationToken)
+    public virtual ValueTask SetApplicationIdAsync(TToken token!!, string? identifier, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         if (!string.IsNullOrEmpty(identifier))
         {
             token.ApplicationId = ObjectId.Parse(identifier);
@@ -625,13 +502,8 @@ public class OpenIddictMongoDbTokenStore<TToken> : IOpenIddictTokenStore<TToken>
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetAuthorizationIdAsync(TToken token, string? identifier, CancellationToken cancellationToken)
+    public virtual ValueTask SetAuthorizationIdAsync(TToken token!!, string? identifier, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         if (!string.IsNullOrEmpty(identifier))
         {
             token.AuthorizationId = ObjectId.Parse(identifier);
@@ -646,54 +518,34 @@ public class OpenIddictMongoDbTokenStore<TToken> : IOpenIddictTokenStore<TToken>
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetCreationDateAsync(TToken token, DateTimeOffset? date, CancellationToken cancellationToken)
+    public virtual ValueTask SetCreationDateAsync(TToken token!!, DateTimeOffset? date, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         token.CreationDate = date?.UtcDateTime;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetExpirationDateAsync(TToken token, DateTimeOffset? date, CancellationToken cancellationToken)
+    public virtual ValueTask SetExpirationDateAsync(TToken token!!, DateTimeOffset? date, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         token.ExpirationDate = date?.UtcDateTime;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetPayloadAsync(TToken token, string? payload, CancellationToken cancellationToken)
+    public virtual ValueTask SetPayloadAsync(TToken token!!, string? payload, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         token.Payload = payload;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetPropertiesAsync(TToken token,
+    public virtual ValueTask SetPropertiesAsync(TToken token!!,
         ImmutableDictionary<string, JsonElement> properties, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
-        if (properties is null || properties.IsEmpty)
+        if (properties is not { IsEmpty: false })
         {
             token.Properties = null;
 
@@ -724,78 +576,48 @@ public class OpenIddictMongoDbTokenStore<TToken> : IOpenIddictTokenStore<TToken>
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetRedemptionDateAsync(TToken token, DateTimeOffset? date, CancellationToken cancellationToken)
+    public virtual ValueTask SetRedemptionDateAsync(TToken token!!, DateTimeOffset? date, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         token.RedemptionDate = date?.UtcDateTime;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetReferenceIdAsync(TToken token, string? identifier, CancellationToken cancellationToken)
+    public virtual ValueTask SetReferenceIdAsync(TToken token!!, string? identifier, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         token.ReferenceId = identifier;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetStatusAsync(TToken token, string? status, CancellationToken cancellationToken)
+    public virtual ValueTask SetStatusAsync(TToken token!!, string? status, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         token.Status = status;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetSubjectAsync(TToken token, string? subject, CancellationToken cancellationToken)
+    public virtual ValueTask SetSubjectAsync(TToken token!!, string? subject, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         token.Subject = subject;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual ValueTask SetTypeAsync(TToken token, string? type, CancellationToken cancellationToken)
+    public virtual ValueTask SetTypeAsync(TToken token!!, string? type, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         token.Type = type;
 
         return default;
     }
 
     /// <inheritdoc/>
-    public virtual async ValueTask UpdateAsync(TToken token, CancellationToken cancellationToken)
+    public virtual async ValueTask UpdateAsync(TToken token!!, CancellationToken cancellationToken)
     {
-        if (token is null)
-        {
-            throw new ArgumentNullException(nameof(token));
-        }
-
         // Generate a new concurrency token and attach it
         // to the token before persisting the changes.
         var timestamp = token.ConcurrencyToken;

src/OpenIddict.Quartz/OpenIddictQuartzBuilder.cs

@@ -18,8 +18,8 @@ public class OpenIddictQuartzBuilder
     /// Initializes a new instance of <see cref="OpenIddictQuartzBuilder"/>.
     /// </summary>
     /// <param name="services">The services collection.</param>
-    public OpenIddictQuartzBuilder(IServiceCollection services)
-        => Services = services ?? throw new ArgumentNullException(nameof(services));
+    public OpenIddictQuartzBuilder(IServiceCollection services!!)
+        => Services = services;
 
     /// <summary>
     /// Gets the services collection.
@@ -33,13 +33,8 @@ public class OpenIddictQuartzBuilder
     /// <param name="configuration">The delegate used to configure the OpenIddict options.</param>
     /// <remarks>This extension can be safely called multiple times.</remarks>
     /// <returns>The <see cref="OpenIddictQuartzBuilder"/>.</returns>
-    public OpenIddictQuartzBuilder Configure(Action<OpenIddictQuartzOptions> configuration)
+    public OpenIddictQuartzBuilder Configure(Action<OpenIddictQuartzOptions> configuration!!)
     {
-        if (configuration is null)
-        {
-            throw new ArgumentNullException(nameof(configuration));
-        }
-
         Services.Configure(configuration);
 
         return this;

src/OpenIddict.Quartz/OpenIddictQuartzConfiguration.cs

@@ -14,13 +14,8 @@ namespace OpenIddict.Quartz;
 public class OpenIddictQuartzConfiguration : IConfigureOptions<QuartzOptions>
 {
     /// <inheritdoc/>
-    public void Configure(QuartzOptions options)
+    public void Configure(QuartzOptions options!!)
     {
-        if (options is null)
-        {
-            throw new ArgumentNullException(nameof(options));
-        }
-
         options.AddJob<OpenIddictQuartzJob>(builder =>
         {
             builder.StoreDurably()

src/OpenIddict.Quartz/OpenIddictQuartzExtensions.cs

@@ -21,13 +21,8 @@ public static class OpenIddictQuartzExtensions
     /// <param name="builder">The services builder used by OpenIddict to register new services.</param>
     /// <remarks>This extension can be safely called multiple times.</remarks>
     /// <returns>The <see cref="OpenIddictQuartzBuilder"/>.</returns>
-    public static OpenIddictQuartzBuilder UseQuartz(this OpenIddictCoreBuilder builder)
+    public static OpenIddictQuartzBuilder UseQuartz(this OpenIddictCoreBuilder builder!!)
     {
-        if (builder is null)
-        {
-            throw new ArgumentNullException(nameof(builder));
-        }
-
         builder.Services.AddQuartz();
 
         // The OpenIddict job is registered as a service to allow
@@ -49,18 +44,8 @@ public static class OpenIddictQuartzExtensions
     /// <remarks>This extension can be safely called multiple times.</remarks>
     /// <returns>The <see cref="OpenIddictCoreBuilder"/>.</returns>
     public static OpenIddictCoreBuilder UseQuartz(
-        this OpenIddictCoreBuilder builder, Action<OpenIddictQuartzBuilder> configuration)
+        this OpenIddictCoreBuilder builder!!, Action<OpenIddictQuartzBuilder> configuration!!)
     {
-        if (builder is null)
-        {
-            throw new ArgumentNullException(nameof(builder));
-        }
-
-        if (configuration is null)
-        {
-            throw new ArgumentNullException(nameof(configuration));
-        }
-
         configuration(builder.UseQuartz());
 
         return builder;

src/OpenIddict.Quartz/OpenIddictQuartzJob.cs

@@ -28,7 +28,7 @@ public class OpenIddictQuartzJob : IJob
     /// </summary>
     /// <param name="options">The OpenIddict Quartz.NET options.</param>
     /// <param name="provider">The service provider.</param>
-    public OpenIddictQuartzJob(IOptionsMonitor<OpenIddictQuartzOptions> options, IServiceProvider provider)
+    public OpenIddictQuartzJob(IOptionsMonitor<OpenIddictQuartzOptions> options!!, IServiceProvider provider!!)
     {
         _options = options;
         _provider = provider;
@@ -42,13 +42,8 @@ public class OpenIddictQuartzJob : IJob
         group: typeof(OpenIddictQuartzJob).Assembly.GetName().Name!);
 
     /// <inheritdoc/>
-    public async Task Execute(IJobExecutionContext context)
+    public async Task Execute(IJobExecutionContext context!!)
     {
-        if (context is null)
-        {
-            throw new ArgumentNullException(nameof(context));
-        }
-
         List<Exception>? exceptions = null;
 
         // Note: this job is registered as a transient service. As such, it cannot directly depend on scoped services