Fix Action Selector Re-entry in ASP.NET Core

samples/aspnetcore/BasicSample/Startup.cs

@@ -10,6 +10,8 @@
     using System.Linq;
     using System.Threading.Tasks;
 
+    using Microsoft.AspNetCore.Mvc.Routing;
+
     public class Startup
     {
         public Startup( IHostingEnvironment env )
@@ -27,7 +29,7 @@ public Startup( IHostingEnvironment env )
         public void ConfigureServices( IServiceCollection services )
         {
             services.AddMvc();
-
+            
             // reporting api versions will return the headers "api-supported-versions" and "api-deprecated-versions"
             services.AddApiVersioning( o => o.ReportApiVersions = true );
         }
@@ -37,6 +39,7 @@ public void Configure( IApplicationBuilder app, IHostingEnvironment env, ILogger
             loggerFactory.AddConsole( Configuration.GetSection( "Logging" ) );
             loggerFactory.AddDebug();
             app.UseMvc();
+            app.UseApiVersioning();
         }
     }
 }

samples/aspnetcore/ByNamespaceSample/Startup.cs

@@ -28,6 +28,7 @@ public void Configure( IApplicationBuilder app, IHostingEnvironment env, ILogger
             }
 
             app.UseMvc();
+            app.UseApiVersioning();
         }
     }
 }

samples/aspnetcore/ConventionsSample/Startup.cs

@@ -54,6 +54,7 @@ public void Configure( IApplicationBuilder app, IHostingEnvironment env, ILogger
             loggerFactory.AddConsole( Configuration.GetSection( "Logging" ) );
             loggerFactory.AddDebug();
             app.UseMvc();
+            app.UseApiVersioning();
         }
     }
 }

samples/aspnetcore/SwaggerSample/Startup.cs

@@ -84,6 +84,7 @@ public void Configure( IApplicationBuilder app, IHostingEnvironment env, ILogger
             loggerFactory.AddDebug();
 
             app.UseMvc();
+            app.UseApiVersioning();
             app.UseSwagger();
             app.UseSwaggerUI(
                 options =>

src/Microsoft.AspNetCore.Mvc.Versioning/Abstractions/ActionDescriptorExtensions.cs

@@ -2,6 +2,7 @@
 {
     using ApplicationModels;
     using System;
+    using System.Collections.Generic;
     using System.Diagnostics.Contracts;
     using System.Linq;
     using Versioning;
@@ -18,6 +19,24 @@ public static class ActionDescriptorExtensions
 
         static void HasAggregatedVersions( this ActionDescriptor action, bool value ) => action.Properties[VersionsAggregated] = value;
 
+        internal static void AggregateAllVersions( this ActionDescriptor action, IEnumerable<ActionDescriptor> matchingActions )
+        {
+            Contract.Requires( action != null );
+            Contract.Requires( matchingActions != null );
+
+            if ( action.HasAggregatedVersions() )
+            {
+                return;
+            }
+
+            action.HasAggregatedVersions( true );
+
+            var model = action.GetProperty<ApiVersionModel>();
+            Contract.Assume( model != null );
+
+            action.SetProperty( model.Aggregate( matchingActions.Select( a => a.GetProperty<ApiVersionModel>() ).Where( m => m != null ) ) );
+        }
+
         internal static void AggregateAllVersions( this ActionDescriptor action, ActionSelectionContext context )
         {
             Contract.Requires( action != null );

src/Microsoft.AspNetCore.Mvc.Versioning/HttpContextExtensions.cs

@@ -1,6 +1,7 @@
 namespace Microsoft.AspNetCore.Mvc
 {
     using Http;
+    using Microsoft.AspNetCore.Mvc.Routing;
     using System;
     using System.Diagnostics.Contracts;
     using Versioning;

src/Microsoft.AspNetCore.Mvc.Versioning/Microsoft.Extensions.DependencyInjection/IApplicationBuilderExtensions.cs

@@ -0,0 +1,28 @@
+namespace Microsoft.Extensions.DependencyInjection
+{
+    using Microsoft.AspNetCore.Builder;
+    using Microsoft.AspNetCore.Mvc.Routing;
+    using System;
+    using System.Diagnostics.Contracts;
+
+    /// <summary>
+    /// Provides extension methods for the <see cref="IApplicationBuilder"/> interface.
+    /// </summary>
+    [CLSCompliant( false )]
+    public static class IApplicationBuilderExtensions
+    {
+        /// <summary>
+        /// Adds API versioning to the <see cref="IApplicationBuilder"/> request execution pipeline.
+        /// </summary>
+        /// <param name="app">The <see cref="IApplicationBuilder">application builder</see> to add API versioning to.</param>
+        /// <returns>The original <see cref="IApplicationBuilder"/>.</returns>
+        public static IApplicationBuilder UseApiVersioning( this IApplicationBuilder app )
+        {
+            Arg.NotNull( app, nameof( app ) );
+            Contract.Ensures( Contract.Result<IApplicationBuilder>() != null );
+
+            app.UseMvc( builder => builder.Routes.Add( builder.ServiceProvider.GetRequiredService<IApiVersionRoutePolicy>() ) );
+            return app;
+        }
+    }
+}

src/Microsoft.AspNetCore.Mvc.Versioning/Microsoft.Extensions.DependencyInjection/IServiceCollectionExtensions.cs

@@ -39,8 +39,10 @@ public static IServiceCollection AddApiVersioning( this IServiceCollection servi
             setupAction( options );
             services.Add( new ServiceDescriptor( typeof( IApiVersionReader ), options.ApiVersionReader ) );
             services.Add( new ServiceDescriptor( typeof( IApiVersionSelector ), options.ApiVersionSelector ) );
+            services.Add( new ServiceDescriptor( typeof( IErrorResponseProvider ), options.ErrorResponses ) );
             services.Add( Singleton<IOptions<ApiVersioningOptions>>( new OptionsWrapper<ApiVersioningOptions>( options ) ) );
             services.Replace( Singleton<IActionSelector, ApiVersionActionSelector>() );
+            services.TryAddSingleton<IApiVersionRoutePolicy, DefaultApiVersionRoutePolicy>();
 
             if ( options.ReportApiVersions )
             {
@@ -58,7 +60,7 @@ public static IServiceCollection AddApiVersioning( this IServiceCollection servi
                     mvcOptions.Conventions.Add( new ApiVersionConvention( options.DefaultApiVersion, options.Conventions ) );
                 } );
 
-            services.AddRouting( mvcOptions => mvcOptions.ConstraintMap.Add( "apiVersion", typeof( ApiVersionRouteConstraint ) ) );
+            services.AddRouting( routeOptions => routeOptions.ConstraintMap.Add( "apiVersion", typeof( ApiVersionRouteConstraint ) ) );
 
             return services;
         }