Use T? on unconstrained type parameters

Directory.Build.props

@@ -4,6 +4,7 @@
 
   <PropertyGroup>
     <LangVersion>preview</LangVersion>
+    <AnalysisLevel>preview</AnalysisLevel>
     <NoWarn>$(NoWarn);CS1591;NU5118;NU5128</NoWarn>
     <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
     <DebugSymbols>true</DebugSymbols>

src/OpenIddict.Core/Managers/OpenIddictApplicationManager.cs

@@ -9,6 +9,7 @@ using System.Buffers.Binary;
 using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.ComponentModel.DataAnnotations;
+using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 using System.Linq;
 using System.Runtime.CompilerServices;
@@ -22,7 +23,6 @@ using Microsoft.Extensions.Options;
 using OpenIddict.Abstractions;
 using static OpenIddict.Abstractions.OpenIddictConstants;
 using SR = OpenIddict.Abstractions.OpenIddictResources;
-using SuppressMessageAttribute = System.Diagnostics.CodeAnalysis.SuppressMessageAttribute;
 
 #if !SUPPORTS_KEY_DERIVATION_WITH_SPECIFIED_HASH_ALGORITHM
 using Org.BouncyCastle.Crypto;
@@ -445,7 +445,7 @@ namespace OpenIddict.Core
                 throw new ArgumentNullException(nameof(query));
             }
 
-            return GetAsync((applications, state) => state(applications), query, cancellationToken);
+            return GetAsync(static (applications, query) => query(applications), query, cancellationToken);
         }
 
         /// <summary>
@@ -862,7 +862,7 @@ namespace OpenIddict.Core
                 throw new ArgumentNullException(nameof(query));
             }
 
-            return ListAsync((applications, state) => state(applications), query, cancellationToken);
+            return ListAsync(static (applications, query) => query(applications), query, cancellationToken);
         }
 
         /// <summary>

src/OpenIddict.Core/Managers/OpenIddictAuthorizationManager.cs

@@ -656,7 +656,7 @@ namespace OpenIddict.Core
                 throw new ArgumentNullException(nameof(query));
             }
 
-            return GetAsync((authorizations, state) => state(authorizations), query, cancellationToken);
+            return GetAsync(static (authorizations, query) => query(authorizations), query, cancellationToken);
         }
 
         /// <summary>
@@ -893,7 +893,7 @@ namespace OpenIddict.Core
                 throw new ArgumentNullException(nameof(query));
             }
 
-            return ListAsync((authorizations, state) => state(authorizations), query, cancellationToken);
+            return ListAsync(static (authorizations, query) => query(authorizations), query, cancellationToken);
         }
 
         /// <summary>

src/OpenIddict.Core/Managers/OpenIddictScopeManager.cs

@@ -383,7 +383,7 @@ namespace OpenIddict.Core
                 throw new ArgumentNullException(nameof(query));
             }
 
-            return GetAsync((scopes, state) => state(scopes), query, cancellationToken);
+            return GetAsync(static (scopes, query) => query(scopes), query, cancellationToken);
         }
 
         /// <summary>
@@ -704,7 +704,7 @@ namespace OpenIddict.Core
                 throw new ArgumentNullException(nameof(query));
             }
 
-            return ListAsync((scopes, state) => state(scopes), query, cancellationToken);
+            return ListAsync(static (scopes, query) => query(scopes), query, cancellationToken);
         }
 
         /// <summary>

src/OpenIddict.Core/Managers/OpenIddictTokenManager.cs

@@ -622,7 +622,7 @@ namespace OpenIddict.Core
                 throw new ArgumentNullException(nameof(query));
             }
 
-            return GetAsync((tokens, state) => state(tokens), query, cancellationToken);
+            return GetAsync(static (tokens, query) => query(tokens), query, cancellationToken);
         }
 
         /// <summary>
@@ -892,7 +892,7 @@ namespace OpenIddict.Core
                 throw new ArgumentNullException(nameof(query));
             }
 
-            return ListAsync((tokens, state) => state(tokens), query, cancellationToken);
+            return ListAsync(static (tokens, query) => query(tokens), query, cancellationToken);
         }
 
         /// <summary>

src/OpenIddict.EntityFramework.Models/OpenIddictEntityFrameworkApplication.cs

@@ -7,7 +7,6 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
-using System.Diagnostics.CodeAnalysis;
 
 namespace OpenIddict.EntityFramework.Models
 {
@@ -74,8 +73,7 @@ namespace OpenIddict.EntityFramework.Models
         /// <summary>
         /// Gets or sets the unique identifier associated with the current application.
         /// </summary>
-        [AllowNull, MaybeNull]
-        public virtual TKey Id { get; set; } = default!;
+        public virtual TKey? Id { get; set; }
 
         /// <summary>
         /// Gets or sets the permissions associated with the

src/OpenIddict.EntityFramework.Models/OpenIddictEntityFrameworkAuthorization.cs

@@ -7,7 +7,6 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
-using System.Diagnostics.CodeAnalysis;
 
 namespace OpenIddict.EntityFramework.Models
 {
@@ -50,8 +49,7 @@ namespace OpenIddict.EntityFramework.Models
         /// <summary>
         /// Gets or sets the unique identifier associated with the current authorization.
         /// </summary>
-        [AllowNull, MaybeNull]
-        public virtual TKey Id { get; set; } = default!;
+        public virtual TKey? Id { get; set; }
 
         /// <summary>
         /// Gets or sets the additional properties serialized as a JSON object,

src/OpenIddict.EntityFramework.Models/OpenIddictEntityFrameworkScope.cs

@@ -6,7 +6,6 @@
 
 using System;
 using System.Diagnostics;
-using System.Diagnostics.CodeAnalysis;
 
 namespace OpenIddict.EntityFramework.Models
 {
@@ -59,8 +58,7 @@ namespace OpenIddict.EntityFramework.Models
         /// <summary>
         /// Gets or sets the unique identifier associated with the current scope.
         /// </summary>
-        [AllowNull, MaybeNull]
-        public virtual TKey Id { get; set; } = default!;
+        public virtual TKey? Id { get; set; }
 
         /// <summary>
         /// Gets or sets the unique name associated with the current scope.

src/OpenIddict.EntityFramework.Models/OpenIddictEntityFrameworkToken.cs

@@ -6,7 +6,6 @@
 
 using System;
 using System.Diagnostics;
-using System.Diagnostics.CodeAnalysis;
 
 namespace OpenIddict.EntityFramework.Models
 {
@@ -59,8 +58,7 @@ namespace OpenIddict.EntityFramework.Models
         /// <summary>
         /// Gets or sets the unique identifier associated with the current token.
         /// </summary>
-        [AllowNull, MaybeNull]
-        public virtual TKey Id { get; set; } = default!;
+        public virtual TKey? Id { get; set; }
 
         /// <summary>
         /// Gets or sets the payload of the current token, if applicable.

src/OpenIddict.EntityFramework/Stores/OpenIddictEntityFrameworkApplicationStore.cs

@@ -11,7 +11,6 @@ using System.ComponentModel;
 using System.Data;
 using System.Data.Entity;
 using System.Data.Entity.Infrastructure;
-using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 using System.IO;
 using System.Linq;
@@ -862,8 +861,7 @@ namespace OpenIddict.EntityFramework
         /// </summary>
         /// <param name="identifier">The identifier to convert.</param>
         /// <returns>An instance of <typeparamref name="TKey"/> representing the provided identifier.</returns>
-        [return: MaybeNull]
-        public virtual TKey ConvertIdentifierFromString(string? identifier)
+        public virtual TKey? ConvertIdentifierFromString(string? identifier)
         {
             if (string.IsNullOrEmpty(identifier))
             {
@@ -878,7 +876,7 @@ namespace OpenIddict.EntityFramework
         /// </summary>
         /// <param name="identifier">The identifier to convert.</param>
         /// <returns>A <see cref="string"/> representation of the provided identifier.</returns>
-        public virtual string? ConvertIdentifierToString([AllowNull] TKey identifier)
+        public virtual string? ConvertIdentifierToString(TKey? identifier)
         {
             if (Equals(identifier, default(TKey)))
             {

src/OpenIddict.EntityFramework/Stores/OpenIddictEntityFrameworkAuthorizationStore.cs

@@ -11,7 +11,6 @@ using System.ComponentModel;
 using System.Data;
 using System.Data.Entity;
 using System.Data.Entity.Infrastructure;
-using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Runtime.CompilerServices;
 using System.Text.Encodings.Web;
@@ -820,8 +819,7 @@ namespace OpenIddict.EntityFramework
         /// </summary>
         /// <param name="identifier">The identifier to convert.</param>
         /// <returns>An instance of <typeparamref name="TKey"/> representing the provided identifier.</returns>
-        [return: MaybeNull]
-        public virtual TKey ConvertIdentifierFromString(string? identifier)
+        public virtual TKey? ConvertIdentifierFromString(string? identifier)
         {
             if (string.IsNullOrEmpty(identifier))
             {
@@ -836,7 +834,7 @@ namespace OpenIddict.EntityFramework
         /// </summary>
         /// <param name="identifier">The identifier to convert.</param>
         /// <returns>A <see cref="string"/> representation of the provided identifier.</returns>
-        public virtual string? ConvertIdentifierToString([AllowNull] TKey identifier)
+        public virtual string? ConvertIdentifierToString(TKey? identifier)
         {
             if (Equals(identifier, default(TKey)))
             {

src/OpenIddict.EntityFramework/Stores/OpenIddictEntityFrameworkScopeStore.cs

@@ -10,7 +10,6 @@ using System.Collections.Immutable;
 using System.ComponentModel;
 using System.Data.Entity;
 using System.Data.Entity.Infrastructure;
-using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 using System.IO;
 using System.Linq;
@@ -630,8 +629,7 @@ namespace OpenIddict.EntityFramework
         /// </summary>
         /// <param name="identifier">The identifier to convert.</param>
         /// <returns>An instance of <typeparamref name="TKey"/> representing the provided identifier.</returns>
-        [return: MaybeNull]
-        public virtual TKey ConvertIdentifierFromString(string? identifier)
+        public virtual TKey? ConvertIdentifierFromString(string? identifier)
         {
             if (string.IsNullOrEmpty(identifier))
             {
@@ -646,7 +644,7 @@ namespace OpenIddict.EntityFramework
         /// </summary>
         /// <param name="identifier">The identifier to convert.</param>
         /// <returns>A <see cref="string"/> representation of the provided identifier.</returns>
-        public virtual string? ConvertIdentifierToString([AllowNull] TKey identifier)
+        public virtual string? ConvertIdentifierToString(TKey? identifier)
         {
             if (Equals(identifier, default(TKey)))
             {

src/OpenIddict.EntityFramework/Stores/OpenIddictEntityFrameworkTokenStore.cs

@@ -11,7 +11,6 @@ using System.ComponentModel;
 using System.Data;
 using System.Data.Entity;
 using System.Data.Entity.Infrastructure;
-using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Text.Encodings.Web;
 using System.Text.Json;
@@ -848,8 +847,7 @@ namespace OpenIddict.EntityFramework
         /// </summary>
         /// <param name="identifier">The identifier to convert.</param>
         /// <returns>An instance of <typeparamref name="TKey"/> representing the provided identifier.</returns>
-        [return: MaybeNull]
-        public virtual TKey ConvertIdentifierFromString(string? identifier)
+        public virtual TKey? ConvertIdentifierFromString(string? identifier)
         {
             if (string.IsNullOrEmpty(identifier))
             {
@@ -864,7 +862,7 @@ namespace OpenIddict.EntityFramework
         /// </summary>
         /// <param name="identifier">The identifier to convert.</param>
         /// <returns>A <see cref="string"/> representation of the provided identifier.</returns>
-        public virtual string? ConvertIdentifierToString([AllowNull] TKey identifier)
+        public virtual string? ConvertIdentifierToString(TKey? identifier)
         {
             if (Equals(identifier, default(TKey)))
             {

src/OpenIddict.EntityFrameworkCore.Models/OpenIddictEntityFrameworkCoreApplication.cs

@@ -7,7 +7,6 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
-using System.Diagnostics.CodeAnalysis;
 
 namespace OpenIddict.EntityFrameworkCore.Models
 {
@@ -82,8 +81,7 @@ namespace OpenIddict.EntityFrameworkCore.Models
         /// <summary>
         /// Gets or sets the unique identifier associated with the current application.
         /// </summary>
-        [AllowNull, MaybeNull]
-        public virtual TKey Id { get; set; } = default!;
+        public virtual TKey? Id { get; set; }
 
         /// <summary>
         /// Gets or sets the permissions associated with the

src/OpenIddict.EntityFrameworkCore.Models/OpenIddictEntityFrameworkCoreAuthorization.cs

@@ -7,7 +7,6 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
-using System.Diagnostics.CodeAnalysis;
 
 namespace OpenIddict.EntityFrameworkCore.Models
 {
@@ -58,8 +57,7 @@ namespace OpenIddict.EntityFrameworkCore.Models
         /// <summary>
         /// Gets or sets the unique identifier associated with the current authorization.
         /// </summary>
-        [AllowNull, MaybeNull]
-        public virtual TKey Id { get; set; } = default!;
+        public virtual TKey? Id { get; set; }
 
         /// <summary>
         /// Gets or sets the additional properties serialized as a JSON object,

src/OpenIddict.EntityFrameworkCore.Models/OpenIddictEntityFrameworkCoreScope.cs

@@ -6,7 +6,6 @@
 
 using System;
 using System.Diagnostics;
-using System.Diagnostics.CodeAnalysis;
 
 namespace OpenIddict.EntityFrameworkCore.Models
 {
@@ -59,8 +58,7 @@ namespace OpenIddict.EntityFrameworkCore.Models
         /// <summary>
         /// Gets or sets the unique identifier associated with the current scope.
         /// </summary>
-        [AllowNull, MaybeNull]
-        public virtual TKey Id { get; set; } = default!;
+        public virtual TKey? Id { get; set; }
 
         /// <summary>
         /// Gets or sets the unique name associated with the current scope.

src/OpenIddict.EntityFrameworkCore.Models/OpenIddictEntityFrameworkCoreToken.cs

@@ -6,7 +6,6 @@
 
 using System;
 using System.Diagnostics;
-using System.Diagnostics.CodeAnalysis;
 
 namespace OpenIddict.EntityFrameworkCore.Models
 {
@@ -67,8 +66,7 @@ namespace OpenIddict.EntityFrameworkCore.Models
         /// <summary>
         /// Gets or sets the unique identifier associated with the current token.
         /// </summary>
-        [AllowNull, MaybeNull]
-        public virtual TKey Id { get; set; } = default!;
+        public virtual TKey? Id { get; set; }
 
         /// <summary>
         /// Gets or sets the payload of the current token, if applicable.

src/OpenIddict.EntityFrameworkCore/Stores/OpenIddictEntityFrameworkCoreApplicationStore.cs

@@ -9,7 +9,6 @@ using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.ComponentModel;
 using System.Data;
-using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 using System.IO;
 using System.Linq;
@@ -912,8 +911,7 @@ namespace OpenIddict.EntityFrameworkCore
         /// </summary>
         /// <param name="identifier">The identifier to convert.</param>
         /// <returns>An instance of <typeparamref name="TKey"/> representing the provided identifier.</returns>
-        [return: MaybeNull]
-        public virtual TKey ConvertIdentifierFromString(string? identifier)
+        public virtual TKey? ConvertIdentifierFromString(string? identifier)
         {
             if (string.IsNullOrEmpty(identifier))
             {
@@ -928,7 +926,7 @@ namespace OpenIddict.EntityFrameworkCore
         /// </summary>
         /// <param name="identifier">The identifier to convert.</param>
         /// <returns>A <see cref="string"/> representation of the provided identifier.</returns>
-        public virtual string? ConvertIdentifierToString([AllowNull] TKey identifier)
+        public virtual string? ConvertIdentifierToString(TKey? identifier)
         {
             if (Equals(identifier, default(TKey)))
             {

src/OpenIddict.EntityFrameworkCore/Stores/OpenIddictEntityFrameworkCoreAuthorizationStore.cs

@@ -9,7 +9,6 @@ using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.ComponentModel;
 using System.Data;
-using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Runtime.CompilerServices;
 using System.Text.Encodings.Web;
@@ -905,8 +904,7 @@ namespace OpenIddict.EntityFrameworkCore
         /// </summary>
         /// <param name="identifier">The identifier to convert.</param>
         /// <returns>An instance of <typeparamref name="TKey"/> representing the provided identifier.</returns>
-        [return: MaybeNull]
-        public virtual TKey ConvertIdentifierFromString(string? identifier)
+        public virtual TKey? ConvertIdentifierFromString(string? identifier)
         {
             if (string.IsNullOrEmpty(identifier))
             {
@@ -921,7 +919,7 @@ namespace OpenIddict.EntityFrameworkCore
         /// </summary>
         /// <param name="identifier">The identifier to convert.</param>
         /// <returns>A <see cref="string"/> representation of the provided identifier.</returns>
-        public virtual string? ConvertIdentifierToString([AllowNull] TKey identifier)
+        public virtual string? ConvertIdentifierToString(TKey? identifier)
         {
             if (Equals(identifier, default(TKey)))
             {

src/OpenIddict.EntityFrameworkCore/Stores/OpenIddictEntityFrameworkCoreScopeStore.cs

@@ -8,7 +8,6 @@ using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.ComponentModel;
-using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 using System.IO;
 using System.Linq;
@@ -646,8 +645,7 @@ namespace OpenIddict.EntityFrameworkCore
         /// </summary>
         /// <param name="identifier">The identifier to convert.</param>
         /// <returns>An instance of <typeparamref name="TKey"/> representing the provided identifier.</returns>
-        [return: MaybeNull]
-        public virtual TKey ConvertIdentifierFromString(string? identifier)
+        public virtual TKey? ConvertIdentifierFromString(string? identifier)
         {
             if (string.IsNullOrEmpty(identifier))
             {
@@ -662,7 +660,7 @@ namespace OpenIddict.EntityFrameworkCore
         /// </summary>
         /// <param name="identifier">The identifier to convert.</param>
         /// <returns>A <see cref="string"/> representation of the provided identifier.</returns>
-        public virtual string? ConvertIdentifierToString([AllowNull] TKey identifier)
+        public virtual string? ConvertIdentifierToString(TKey? identifier)
         {
             if (Equals(identifier, default(TKey)))
             {

src/OpenIddict.EntityFrameworkCore/Stores/OpenIddictEntityFrameworkCoreTokenStore.cs

@@ -9,7 +9,6 @@ using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.ComponentModel;
 using System.Data;
-using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Text.Encodings.Web;
 using System.Text.Json;
@@ -918,8 +917,7 @@ namespace OpenIddict.EntityFrameworkCore
         /// </summary>
         /// <param name="identifier">The identifier to convert.</param>
         /// <returns>An instance of <typeparamref name="TKey"/> representing the provided identifier.</returns>
-        [return: MaybeNull]
-        public virtual TKey ConvertIdentifierFromString(string? identifier)
+        public virtual TKey? ConvertIdentifierFromString(string? identifier)
         {
             if (string.IsNullOrEmpty(identifier))
             {
@@ -934,7 +932,7 @@ namespace OpenIddict.EntityFrameworkCore
         /// </summary>
         /// <param name="identifier">The identifier to convert.</param>
         /// <returns>A <see cref="string"/> representation of the provided identifier.</returns>
-        public virtual string? ConvertIdentifierToString([AllowNull] TKey identifier)
+        public virtual string? ConvertIdentifierToString(TKey? identifier)
         {
             if (Equals(identifier, default(TKey)))
             {

src/OpenIddict.Server/OpenIddictServerBuilder.cs

@@ -6,6 +6,7 @@
 
 using System;
 using System.ComponentModel;
+using System.Diagnostics.CodeAnalysis;
 using System.IO;
 using System.Linq;
 using System.Reflection;
@@ -17,7 +18,6 @@ using Microsoft.IdentityModel.Tokens;
 using OpenIddict.Server;
 using static OpenIddict.Abstractions.OpenIddictConstants;
 using SR = OpenIddict.Abstractions.OpenIddictResources;
-using SuppressMessageAttribute = System.Diagnostics.CodeAnalysis.SuppressMessageAttribute;
 
 namespace Microsoft.Extensions.DependencyInjection
 {

src/OpenIddict.Validation/OpenIddictValidationBuilder.cs

@@ -6,6 +6,7 @@
 
 using System;
 using System.ComponentModel;
+using System.Diagnostics.CodeAnalysis;
 using System.IO;
 using System.Linq;
 using System.Reflection;
@@ -16,7 +17,6 @@ using Microsoft.IdentityModel.Protocols.OpenIdConnect;
 using Microsoft.IdentityModel.Tokens;
 using OpenIddict.Validation;
 using SR = OpenIddict.Abstractions.OpenIddictResources;
-using SuppressMessageAttribute = System.Diagnostics.CodeAnalysis.SuppressMessageAttribute;
 
 namespace Microsoft.Extensions.DependencyInjection
 {