Introduce module naming to prevent multiple registrations

src/OpenIddict.Assets/OpenIddictExtensions.cs

@@ -12,7 +12,7 @@ using Microsoft.Extensions.Internal;
 namespace Microsoft.AspNet.Builder {
     public static class OpenIddictExtensions {
         public static OpenIddictBuilder UseAssets([NotNull] this OpenIddictBuilder builder) {
-            return builder.AddModule(-20, app => app.UseStaticFiles(new StaticFileOptions {
+            return builder.AddModule("Assets", -20, app => app.UseStaticFiles(new StaticFileOptions {
                 FileProvider = new EmbeddedFileProvider(
                     assembly: Assembly.Load(new AssemblyName("OpenIddict.Assets")),
                     baseNamespace: "OpenIddict.Assets")

src/OpenIddict.Core/OpenIddictExtensions.cs

@@ -46,9 +46,16 @@ namespace Microsoft.AspNet.Builder {
         }
 
         public static OpenIddictBuilder AddModule(
-            [NotNull] this OpenIddictBuilder builder, int position,
+            [NotNull] this OpenIddictBuilder builder,
+            [NotNull] string name, int position,
             [NotNull] Action<IApplicationBuilder> registration) {
+            // By default, prevent duplicate registrations.
+            if (builder.Modules.Any(module => string.Equals(module.Name, name))) {
+                return builder;
+            }
+
             builder.Modules.Add(new OpenIddictModule {
+                Name = name,
                 Position = position,
                 Registration = registration
             });
@@ -74,7 +81,7 @@ namespace Microsoft.AspNet.Builder {
 
             configuration(builder);
 
-            builder.AddModule(-10, map => map.UseCors(options => {
+            builder.AddModule("CORS", -10, map => map.UseCors(options => {
                 options.AllowAnyHeader();
                 options.AllowAnyMethod();
                 options.AllowAnyOrigin();
@@ -82,7 +89,7 @@ namespace Microsoft.AspNet.Builder {
             }));
 
             // Add OpenIdConnectServerMiddleware to the ASP.NET 5 pipeline.
-            builder.AddModule(0, map => map.UseOpenIdConnectServer(builder.Options));
+            builder.AddModule("ASOS", 0, map => map.UseOpenIdConnectServer(builder.Options));
 
             // Register the OpenIddict modules in the ASP.NET 5 pipeline.
             foreach (var module in builder.Modules.OrderBy(module => module.Position)) {

src/OpenIddict.Core/OpenIddictModule.cs

@@ -6,6 +6,11 @@ namespace OpenIddict {
     /// Defines an OpenIddict module.
     /// </summary>
     public class OpenIddictModule {
+        /// <summary>
+        /// Gets or sets the name of the module.
+        /// </summary>
+        public string Name { get; set; }
+
         /// <summary>
         /// Gets or sets the position of the module in the ASP.NET pipeline.
         /// </summary>

src/OpenIddict.Mvc/OpenIddictController.cs

@@ -18,7 +18,7 @@ using Microsoft.AspNet.Mvc;
 using Microsoft.Extensions.Internal;
 using Microsoft.IdentityModel.Protocols.OpenIdConnect;
 
-namespace OpenIddict {
+namespace OpenIddict.Mvc {
     // Note: this controller is generic and doesn't need to be marked as internal to prevent MVC from discovering it.
     public class OpenIddictController<TUser, TApplication> : Controller where TUser : class where TApplication : class {
         public OpenIddictController(

src/OpenIddict.Mvc/OpenIddictExtensions.cs

@@ -15,11 +15,12 @@ using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Internal;
 using NWebsec.Middleware;
 using OpenIddict;
+using OpenIddict.Mvc;
 
 namespace Microsoft.AspNet.Builder {
     public static class OpenIddictExtensions {
         public static OpenIddictBuilder UseMvc([NotNull] this OpenIddictBuilder builder) {
-            builder.AddModule(-20, app => {
+            builder.AddModule("NWebsec", -20, app => {
                 // Insert a new middleware responsible of setting the Content-Security-Policy header.
                 // See https://nwebsec.codeplex.com/wikipage?title=Configuring%20Content%20Security%20Policy&referringTitle=NWebsec
                 app.UseCsp(options => options.DefaultSources(directive => directive.Self())
@@ -41,7 +42,7 @@ namespace Microsoft.AspNet.Builder {
             });
 
             // Run the rest of the pipeline in an isolated environment.
-            builder.AddModule(10, app => app.Isolate(map => map.UseMvc(routes => {
+            builder.AddModule("MVC", 10, app => app.Isolate(map => map.UseMvc(routes => {
                 // Register the actions corresponding to the authorization endpoint.
                 if (builder.Options.AuthorizationEndpointPath.HasValue) {
                     routes.MapRoute("{D97891B4}", builder.Options.AuthorizationEndpointPath.Value.Substring(1), new {
@@ -83,7 +84,7 @@ namespace Microsoft.AspNet.Builder {
                             options.FileProvider,
                             new EmbeddedFileProvider(
                                 assembly: typeof(OpenIddictController<,>).GetTypeInfo().Assembly,
-                                baseNamespace: "OpenIddict.Mvc"));
+                                baseNamespace: typeof(OpenIddictController<,>).Namespace));
                     });
 
                 // Register the sign-in manager in the isolated container.