Testing additional functionalities

Author: JunTaoLuo

src/Microsoft.AspNet.Owin/OwinExtensions.cs

@@ -78,7 +78,7 @@ public static IApplicationBuilder UseBuilder(this AddMiddleware app, Action<ISer
             }
             var builder = new ApplicationBuilder(serviceProvider: services?.BuildServiceProvider());
 
-            CreateMiddleware middleware = CreateMiddlewareFactory(exit =>
+            var middleware = CreateMiddlewareFactory(exit =>
             {
                 builder.Use(ignored => exit);
                 return builder.Build();

test/Microsoft.AspNet.Owin.Tests/OwinExtensionTests.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using System.Threading.Tasks;
 using Microsoft.AspNet.Builder;
 using Microsoft.Extensions.DependencyInjection;
@@ -11,6 +12,7 @@
 
 namespace Microsoft.AspNet.Owin
 {
+    using AppFunc = Func<IDictionary<string, object>, Task>;
     using CreateMiddleware = Func<
           Func<IDictionary<string, object>, Task>,
           Func<IDictionary<string, object>, Task>
@@ -22,22 +24,32 @@ namespace Microsoft.AspNet.Owin
 
     public class OwinExtensionTests
     {
+        static AppFunc notFound = async env => env["owin.ResponseStatusCode"] = 404;
+
         [Fact]
         public void OwinConfigureServicesAddsServices()
         {
-            AddMiddleware build = new List<CreateMiddleware>().Add;
+            IList<CreateMiddleware> list = new List<CreateMiddleware>();
+            AddMiddleware build = list.Add;
             IServiceProvider serviceProvider = null;
+            FakeService fakeService = null;
 
             var builder = build.UseBuilder(applicationBuilder =>
             {
                 serviceProvider = applicationBuilder.ApplicationServices;
-            }
-            , serviceCollection =>
+                applicationBuilder.Run(async context =>
+                {
+                    fakeService = context.ApplicationServices.GetService<FakeService>();
+                });
+            }, serviceCollection =>
             {
                 serviceCollection.AddInstance(new FakeService());
             });
 
-            Assert.NotNull(serviceProvider);
+            list.Reverse().Aggregate(notFound, (next, middleware) => middleware(next)).Invoke(new Dictionary<string, object>());
+
+            Assert.NotNull(fakeService);
+            Assert.NotNull(serviceProvider?.GetService<FakeService>());
         }
 
         public class FakeService