Refactoring IServerFactory #395

src/Microsoft.AspNet.Hosting.Server.Abstractions/IServer.cs

@@ -0,0 +1,26 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using Microsoft.AspNet.Http;
+using Microsoft.AspNet.Http.Features;
+
+namespace Microsoft.AspNet.Hosting.Server
+{
+    /// <summary>
+    /// Represents a server.
+    /// </summary>
+    public interface IServer : IDisposable
+    {
+        /// <summary>
+        /// A collection of HTTP features of the server.
+        /// </summary>
+        IFeatureCollection Features { get; }
+
+        /// <summary>
+        /// Start the server with the given function that processes an HTTP request.
+        /// </summary>
+        /// <param name="requestDelegate">A function that processes an HTTP request.</param>
+        void Start(RequestDelegate requestDelegate);
+    }
+}

src/Microsoft.AspNet.Hosting.Server.Abstractions/IServerFactory.cs

@@ -1,16 +1,20 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-using System;
-using System.Threading.Tasks;
-using Microsoft.AspNet.Http.Features;
 using Microsoft.Extensions.Configuration;
 
 namespace Microsoft.AspNet.Hosting.Server
 {
+    /// <summary>
+    /// Represents a factory for creating servers.
+    /// </summary>
     public interface IServerFactory
     {
-        IFeatureCollection Initialize(IConfiguration configuration);
+        /// <summary>
-        IDisposable Start(IFeatureCollection serverFeatures, Func<IFeatureCollection, Task> application);
+        /// Creates <see cref="IServer"/> based on the given configuration.
+        /// </summary>
+        /// <param name="configuration">An instance of <see cref="IConfiguration"/>.</param>
+        /// <returns>The created server.</returns>
+        IServer CreateServer(IConfiguration configuration);
     }
 }

src/Microsoft.AspNet.Hosting.Server.Abstractions/project.json

@@ -6,11 +6,11 @@
     "url": "git://github.com/aspnet/hosting"
   },
   "dependencies": {
-    "Microsoft.AspNet.Http.Features": "1.0.0-*",
+    "Microsoft.AspNet.Http.Abstractions": "1.0.0-*",
     "Microsoft.Extensions.Configuration.Abstractions": "1.0.0-*"
   },
   "frameworks": {
     "net451": {},
     "dotnet5.4": {}
   }
-}
+}

src/Microsoft.AspNet.Hosting/Internal/HostingEngine.cs

@@ -42,7 +42,7 @@ namespace Microsoft.AspNet.Hosting.Internal
         // Only one of these should be set
         internal IServerFactory ServerFactory { get; set; }
         internal string ServerFactoryLocation { get; set; }
-        private IFeatureCollection _serverFeatures;
+        internal IServer Server { get; set; }
 
         public HostingEngine(
             IServiceCollection appServices,
@@ -87,15 +87,13 @@ namespace Microsoft.AspNet.Hosting.Internal
             var application = BuildApplication();
 
             var logger = _applicationServices.GetRequiredService<ILogger<HostingEngine>>();
-            var contextFactory = _applicationServices.GetRequiredService<IHttpContextFactory>();
             var diagnosticSource = _applicationServices.GetRequiredService<DiagnosticSource>();
 
             logger.Starting();
 
-            var server = ServerFactory.Start(_serverFeatures,
+            Server.Start(
-                async features =>
+                async httpContext =>
                 {
-                    var httpContext = contextFactory.Create(features);
                     httpContext.ApplicationServices = _applicationServices;
 
                     if (diagnosticSource.IsEnabled("Microsoft.AspNet.Hosting.BeginRequest"))
@@ -135,11 +133,11 @@ namespace Microsoft.AspNet.Hosting.Internal
             _applicationLifetime.NotifyStarted();
             logger.Started();
 
-            return new Application(ApplicationServices, _serverFeatures, new Disposable(() =>
+            return new Application(ApplicationServices, Server.Features, new Disposable(() =>
             {
                 logger.Shutdown();
                 _applicationLifetime.StopApplication();
-                server.Dispose();
+                Server.Dispose();
                 _applicationLifetime.NotifyStopped();
                 (_applicationServices as IDisposable)?.Dispose();
             }));
@@ -191,7 +189,7 @@ namespace Microsoft.AspNet.Hosting.Internal
                 EnsureServer();
 
                 var builderFactory = _applicationServices.GetRequiredService<IApplicationBuilderFactory>();
-                var builder = builderFactory.CreateBuilder(_serverFeatures);
+                var builder = builderFactory.CreateBuilder(Server.Features);
                 builder.ApplicationServices = _applicationServices;
 
                 var startupFilters = _applicationServices.GetService<IEnumerable<IStartupFilter>>();
@@ -246,21 +244,21 @@ namespace Microsoft.AspNet.Hosting.Internal
 
         private void EnsureServer()
         {
-            if (ServerFactory == null)
+            if (Server == null)
             {
-                // Blow up if we don't have a server set at this point
+                if (ServerFactory == null)
-                if (ServerFactoryLocation == null)
                 {
-                    throw new InvalidOperationException("IHostingBuilder.UseServer() is required for " + nameof(Start) + "()");
+                    // Blow up if we don't have a server set at this point
+                    if (ServerFactoryLocation == null)
+                    {
+                        throw new InvalidOperationException("IHostingBuilder.UseServer() is required for " + nameof(Start) + "()");
+                    }
+
+                    ServerFactory = _applicationServices.GetRequiredService<IServerLoader>().LoadServerFactory(ServerFactoryLocation);
                 }
 
-                ServerFactory = _applicationServices.GetRequiredService<IServerLoader>().LoadServerFactory(ServerFactoryLocation);
+                Server = ServerFactory.CreateServer(_config);
-            }
+                var addresses = Server.Features?.Get<IServerAddressesFeature>()?.Addresses;
-
-            if (_serverFeatures == null)
-            {
-                _serverFeatures = ServerFactory.Initialize(_config);
-                var addresses = _serverFeatures?.Get<IServerAddressesFeature>()?.Addresses;
                 if (addresses != null && !addresses.IsReadOnly)
                 {
                     var port = _config[ServerPort];

src/Microsoft.AspNet.Hosting/WebHostBuilder.cs

@@ -42,6 +42,7 @@ namespace Microsoft.AspNet.Hosting
         // Only one of these should be set
         private string _serverFactoryLocation;
         private IServerFactory _serverFactory;
+        private IServer _server;
 
         public WebHostBuilder()
             : this(config: new ConfigurationBuilder().Build())
@@ -133,6 +134,7 @@ namespace Microsoft.AspNet.Hosting
             var engine = new HostingEngine(hostingServices, startupLoader, _config, _captureStartupErrors);
 
             // Only one of these should be set, but they are used in priority
+            engine.Server = _server;
             engine.ServerFactory = _serverFactory;
             engine.ServerFactoryLocation = _config[ServerKey] ?? _config[OldServerKey] ?? _serverFactoryLocation;
 
@@ -161,7 +163,18 @@ namespace Microsoft.AspNet.Hosting
             return this;
         }
 
-        public WebHostBuilder UseServer(string assemblyName)
+        public WebHostBuilder UseServer(IServer server)
+        {
+            if (server == null)
+            {
+                throw new ArgumentNullException(nameof(server));
+            }
+
+            _server = server;
+            return this;
+        }
+
+        public WebHostBuilder UseServerFactory(string assemblyName)
         {
             if (assemblyName == null)
             {
@@ -172,8 +185,13 @@ namespace Microsoft.AspNet.Hosting
             return this;
         }
 
-        public WebHostBuilder UseServer(IServerFactory factory)
+        public WebHostBuilder UseServerFactory(IServerFactory factory)
         {
+            if (factory == null)
+            {
+                throw new ArgumentNullException(nameof(factory));
+            }
+
             _serverFactory = factory;
             return this;
         }

src/Microsoft.AspNet.TestHost/ClientHandler.cs

@@ -23,21 +23,27 @@ namespace Microsoft.AspNet.TestHost
     /// </summary>
     public class ClientHandler : HttpMessageHandler
     {
-        private readonly Func<IFeatureCollection, Task> _next;
+        private readonly RequestDelegate _next;
         private readonly PathString _pathBase;
+        private readonly IHttpContextFactory _factory;
 
         /// <summary>
         /// Create a new handler.
         /// </summary>
         /// <param name="next">The pipeline entry point.</param>
-        public ClientHandler(Func<IFeatureCollection, Task> next, PathString pathBase)
+        public ClientHandler(RequestDelegate next, PathString pathBase, IHttpContextFactory httpContextFactory)
         {
             if (next == null)
             {
                 throw new ArgumentNullException(nameof(next));
             }
+            if (httpContextFactory == null)
+            {
+                throw new ArgumentNullException(nameof(httpContextFactory));
+            }
 
             _next = next;
+            _factory = httpContextFactory;
 
             // PathString.StartsWithSegments that we use below requires the base path to not end in a slash.
             if (pathBase.HasValue && pathBase.Value.EndsWith("/"))
@@ -63,7 +69,7 @@ namespace Microsoft.AspNet.TestHost
                 throw new ArgumentNullException(nameof(request));
             }
 
-            var state = new RequestState(request, _pathBase);
+            var state = new RequestState(request, _pathBase, _factory);
             var requestContent = request.Content ?? new StreamContent(Stream.Null);
             var body = await requestContent.ReadAsStreamAsync();
             if (body.CanSeek)
@@ -79,7 +85,7 @@ namespace Microsoft.AspNet.TestHost
                 {
                     try
                     {
-                        await _next(state.HttpContext.Features);
+                        await _next(state.HttpContext);
                         state.CompleteResponse();
                     }
                     catch (Exception ex)
@@ -88,6 +94,7 @@ namespace Microsoft.AspNet.TestHost
                     }
                     finally
                     {
+                        state.ServerCleanup();
                         registration.Dispose();
                     }
                 });
@@ -102,14 +109,16 @@ namespace Microsoft.AspNet.TestHost
             private ResponseStream _responseStream;
             private ResponseFeature _responseFeature;
             private CancellationTokenSource _requestAbortedSource;
+            private IHttpContextFactory _factory;
             private bool _pipelineFinished;
 
-            internal RequestState(HttpRequestMessage request, PathString pathBase)
+            internal RequestState(HttpRequestMessage request, PathString pathBase, IHttpContextFactory factory)
             {
                 _request = request;
                 _responseTcs = new TaskCompletionSource<HttpResponseMessage>();
                 _requestAbortedSource = new CancellationTokenSource();
                 _pipelineFinished = false;
+                _factory = factory;
 
                 if (request.RequestUri.IsDefaultPort)
                 {
@@ -120,7 +129,8 @@ namespace Microsoft.AspNet.TestHost
                     request.Headers.Host = request.RequestUri.GetComponents(UriComponents.HostAndPort, UriFormat.UriEscaped);
                 }
 
-                HttpContext = new DefaultHttpContext();
+                HttpContext = _factory.Create(new FeatureCollection());
+                
                 HttpContext.Features.Set<IHttpRequestFeature>(new RequestFeature());
                 _responseFeature = new ResponseFeature();
                 HttpContext.Features.Set<IHttpResponseFeature>(_responseFeature);
@@ -228,6 +238,14 @@ namespace Microsoft.AspNet.TestHost
                 _responseStream.Abort(exception);
                 _responseTcs.TrySetException(exception);
             }
+
+            internal void ServerCleanup()
+            {
+                if (HttpContext != null)
+                {
+                    _factory.Dispose(HttpContext);
+                }
+            }
         }
     }
 }

src/Microsoft.AspNet.TestHost/TestServer.cs

@@ -1,4 +1,4 @@
-// Copyright (c) .NET Foundation. All rights reserved.
+// Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
@@ -14,22 +14,26 @@ using Microsoft.Extensions.DependencyInjection;
 
 namespace Microsoft.AspNet.TestHost
 {
-    public class TestServer : IServerFactory, IDisposable
+    public class TestServer : IServer
     {
         private const string DefaultEnvironmentName = "Development";
         private const string ServerName = nameof(TestServer);
-        private static readonly IFeatureCollection ServerInfo = new FeatureCollection();
+        private RequestDelegate _appDelegate;
-        private Func<IFeatureCollection, Task> _appDelegate;
         private IDisposable _appInstance;
         private bool _disposed = false;
+        private IHttpContextFactory _httpContextFactory;
 
         public TestServer(WebHostBuilder builder)
         {
-            _appInstance = builder.UseServer(this).Build().Start();
+            var hostingEngine = builder.UseServer(this).Build();
+            _httpContextFactory = hostingEngine.ApplicationServices.GetService<IHttpContextFactory>();
+            _appInstance = hostingEngine.Start();
         }
 
         public Uri BaseAddress { get; set; } = new Uri("http://localhost/");
 
+        IFeatureCollection IServer.Features { get; }
+
         public static TestServer Create()
         {
             return Create(config: null, configureApp: null, configureServices: null);
@@ -95,7 +99,7 @@ namespace Microsoft.AspNet.TestHost
         public HttpMessageHandler CreateHandler()
         {
             var pathBase = BaseAddress == null ? PathString.Empty : PathString.FromUriComponent(BaseAddress);
-            return new ClientHandler(Invoke, pathBase);
+            return new ClientHandler(Invoke, pathBase, _httpContextFactory);
         }
 
         public HttpClient CreateClient()
@@ -106,7 +110,7 @@ namespace Microsoft.AspNet.TestHost
         public WebSocketClient CreateWebSocketClient()
         {
             var pathBase = BaseAddress == null ? PathString.Empty : PathString.FromUriComponent(BaseAddress);
-            return new WebSocketClient(Invoke, pathBase);
+            return new WebSocketClient(Invoke, pathBase, _httpContextFactory);
         }
 
         /// <summary>
@@ -119,25 +123,13 @@ namespace Microsoft.AspNet.TestHost
             return new RequestBuilder(this, path);
         }
 
-        public IFeatureCollection Initialize(IConfiguration configuration)
+        public Task Invoke(HttpContext context)
-        {
-            return ServerInfo;
-        }
-
-        public IDisposable Start(IFeatureCollection serverInformation, Func<IFeatureCollection, Task> application)
-        {
-            _appDelegate = application;
-
-            return this;
-        }
-
-        public Task Invoke(IFeatureCollection featureCollection)
         {
             if (_disposed)
             {
                 throw new ObjectDisposedException(GetType().FullName);
             }
-            return _appDelegate(featureCollection);
+            return _appDelegate(context);
         }
 
         public void Dispose()
@@ -145,5 +137,10 @@ namespace Microsoft.AspNet.TestHost
             _disposed = true;
             _appInstance.Dispose();
         }
+
+        void IServer.Start(RequestDelegate requestDelegate)
+        {
+            _appDelegate = requestDelegate;
+        }
     }
 }

src/Microsoft.AspNet.TestHost/WebSocketClient.cs

@@ -8,25 +8,31 @@ using System.Net.WebSockets;
 using System.Security.Cryptography;
 using System.Threading;
 using System.Threading.Tasks;
-using Microsoft.AspNet.Http.Features;
 using Microsoft.AspNet.Http;
+using Microsoft.AspNet.Http.Features;
 using Microsoft.AspNet.Http.Internal;
 
 namespace Microsoft.AspNet.TestHost
 {
     public class WebSocketClient
     {
-        private readonly Func<IFeatureCollection, Task> _next;
+        private readonly RequestDelegate _next;
         private readonly PathString _pathBase;
+        private readonly IHttpContextFactory _httpContextFactory;
 
-        internal WebSocketClient(Func<IFeatureCollection, Task> next, PathString pathBase)
+        internal WebSocketClient(RequestDelegate next, PathString pathBase, IHttpContextFactory httpContextFactory)
         {
             if (next == null)
             {
                 throw new ArgumentNullException(nameof(next));
             }
+            if (httpContextFactory == null)
+            {
+                throw new ArgumentNullException(nameof(httpContextFactory));
+            }
 
             _next = next;
+            _httpContextFactory = httpContextFactory;
 
             // PathString.StartsWithSegments that we use below requires the base path to not end in a slash.
             if (pathBase.HasValue && pathBase.Value.EndsWith("/"))
@@ -52,7 +58,7 @@ namespace Microsoft.AspNet.TestHost
 
         public async Task<WebSocket> ConnectAsync(Uri uri, CancellationToken cancellationToken)
         {
-            var state = new RequestState(uri, _pathBase, cancellationToken);
+            var state = new RequestState(uri, _pathBase, cancellationToken, _httpContextFactory);
 
             if (ConfigureRequest != null)
             {
@@ -64,7 +70,7 @@ namespace Microsoft.AspNet.TestHost
             {
                 try
                 {
-                    await _next(state.FeatureCollection);
+                    await _next(state.HttpContext);
                     state.PipelineComplete();
                 }
                 catch (Exception ex)
@@ -84,18 +90,18 @@ namespace Microsoft.AspNet.TestHost
         {
             private TaskCompletionSource<WebSocket> _clientWebSocketTcs;
             private WebSocket _serverWebSocket;
+            private IHttpContextFactory _factory;
 
-            public IFeatureCollection FeatureCollection { get; private set; }
             public HttpContext HttpContext { get; private set; }
             public Task<WebSocket> WebSocketTask { get { return _clientWebSocketTcs.Task; } }
 
-            public RequestState(Uri uri, PathString pathBase, CancellationToken cancellationToken)
+            public RequestState(Uri uri, PathString pathBase, CancellationToken cancellationToken, IHttpContextFactory factory)
             {
+                _factory = factory;
                 _clientWebSocketTcs = new TaskCompletionSource<WebSocket>();
 
                 // HttpContext
-                FeatureCollection = new FeatureCollection();
+                HttpContext = _factory.Create(new FeatureCollection());
-                HttpContext = new DefaultHttpContext(FeatureCollection);
 
                 // Request
                 HttpContext.Features.Set<IHttpRequestFeature>(new RequestFeature());
@@ -147,6 +153,10 @@ namespace Microsoft.AspNet.TestHost
 
             public void Dispose()
             {
+                if (HttpContext != null)
+                {
+                    _factory.Dispose(HttpContext);
+                }
                 if (_serverWebSocket != null)
                 {
                     _serverWebSocket.Dispose();

test/Microsoft.AspNet.Hosting.Tests/HostingEngineTests.cs

@@ -14,6 +14,7 @@ using Microsoft.AspNet.Hosting.Server;
 using Microsoft.AspNet.Hosting.Startup;
 using Microsoft.AspNet.Http;
 using Microsoft.AspNet.Http.Features;
+using Microsoft.AspNet.Http.Internal;
 using Microsoft.AspNet.Server.Features;
 using Microsoft.AspNet.Testing.xunit;
 using Microsoft.Extensions.Configuration;
@@ -26,10 +27,33 @@ using Xunit;
 
 namespace Microsoft.AspNet.Hosting
 {
-    public class HostingEngineTests : IServerFactory
+    public class HostingEngineTests : IServerFactory, IServer
     {
         private readonly IList<StartInstance> _startInstances = new List<StartInstance>();
         private IFeatureCollection _featuresSupportedByThisHost = NewFeatureCollection();
+        private IFeatureCollection _instanceFeaturesSupportedByThisHost;
+
+        public IFeatureCollection Features {
+            get
+            {
+                var features = new FeatureCollection();
+
+                foreach (var feature in _featuresSupportedByThisHost)
+                {
+                    features[feature.Key] = feature.Value;
+                }
+
+                if (_instanceFeaturesSupportedByThisHost != null)
+                {
+                    foreach (var feature in _instanceFeaturesSupportedByThisHost)
+                    {
+                        features[feature.Key] = feature.Value;
+                    }
+                }
+
+                return features;
+            }
+        }
 
         static IFeatureCollection NewFeatureCollection()
         {
@@ -431,26 +455,36 @@ namespace Microsoft.AspNet.Hosting
             return new WebHostBuilder(config ?? new ConfigurationBuilder().Build());
         }
 
-        public IFeatureCollection Initialize(IConfiguration configuration)
+        public void Start(RequestDelegate requestDelegate)
         {
-            var features = new FeatureCollection();
+            var startInstance = new StartInstance(requestDelegate);
-            features.Set<IServerAddressesFeature>(new ServerAddressesFeature());
-            return features;
-        }
-
-        public IDisposable Start(IFeatureCollection serverFeatures, Func<IFeatureCollection, Task> application)
-        {
-            var startInstance = new StartInstance(application);
             _startInstances.Add(startInstance);
-            application(_featuresSupportedByThisHost);
+            requestDelegate(new DefaultHttpContext(Features));
-            return startInstance;
         }
 
-        public class StartInstance : IDisposable
+        public void Dispose()
         {
-            private readonly Func<IFeatureCollection, Task> _application;
+            if (_startInstances != null)
+            {
+                foreach (var startInstance in _startInstances)
+                {
+                    startInstance.Dispose();
+                }
+            }
+        }
 
-            public StartInstance(Func<IFeatureCollection, Task> application)
+        public IServer CreateServer(IConfiguration configuration)
+        {
+            _instanceFeaturesSupportedByThisHost = new FeatureCollection();
+            _instanceFeaturesSupportedByThisHost.Set<IServerAddressesFeature>(new ServerAddressesFeature());
+            return this;
+        }
+
+        private class StartInstance : IDisposable
+        {
+            private readonly RequestDelegate _application;
+
+            public StartInstance(RequestDelegate application)
             {
                 _application = application;
             }

test/Microsoft.AspNet.Hosting.Tests/WebHostBuilderTests.cs

@@ -1,13 +1,13 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Threading.Tasks;
 using Microsoft.AspNet.Hosting.Fakes;
 using Microsoft.AspNet.Hosting.Internal;
 using Microsoft.AspNet.Hosting.Server;
+using Microsoft.AspNet.Http;
 using Microsoft.AspNet.Http.Features;
 using Microsoft.AspNet.Http.Internal;
 using Microsoft.Extensions.Configuration;
@@ -42,11 +42,11 @@ namespace Microsoft.AspNet.Hosting
         public async Task StartupMissing_Fallback()
         {
             var builder = CreateWebHostBuilder();
-            var serverFactory = new TestServerFactory();
+            var server = new TestServer();
-            var engine = builder.UseServer(serverFactory).UseStartup("MissingStartupAssembly").Build();
+            var engine = builder.UseServer(server).UseStartup("MissingStartupAssembly").Build();
             using (engine.Start())
             {
-                await AssertResponseContains(serverFactory.Application, "MissingStartupAssembly");
+                await AssertResponseContains(server.RequestDelegate, "MissingStartupAssembly");
             }
         }
 
@@ -54,11 +54,11 @@ namespace Microsoft.AspNet.Hosting
         public async Task StartupStaticCtorThrows_Fallback()
         {
             var builder = CreateWebHostBuilder();
-            var serverFactory = new TestServerFactory();
+            var server = new TestServer();
-            var engine = builder.UseServer(serverFactory).UseStartup<StartupStaticCtorThrows>().Build();
+            var engine = builder.UseServer(server).UseStartup<StartupStaticCtorThrows>().Build();
             using (engine.Start())
             {
-                await AssertResponseContains(serverFactory.Application, "Exception from static constructor");
+                await AssertResponseContains(server.RequestDelegate, "Exception from static constructor");
             }
         }
 
@@ -66,11 +66,11 @@ namespace Microsoft.AspNet.Hosting
         public async Task StartupCtorThrows_Fallback()
         {
             var builder = CreateWebHostBuilder();
-            var serverFactory = new TestServerFactory();
+            var server = new TestServer();
-            var engine = builder.UseServer(serverFactory).UseStartup<StartupCtorThrows>().Build();
+            var engine = builder.UseServer(server).UseStartup<StartupCtorThrows>().Build();
             using (engine.Start())
             {
-                await AssertResponseContains(serverFactory.Application, "Exception from constructor");
+                await AssertResponseContains(server.RequestDelegate, "Exception from constructor");
             }
         }
 
@@ -78,11 +78,11 @@ namespace Microsoft.AspNet.Hosting
         public async Task StartupCtorThrows_TypeLoadException()
         {
             var builder = CreateWebHostBuilder();
-            var serverFactory = new TestServerFactory();
+            var server = new TestServer();
-            var engine = builder.UseServer(serverFactory).UseStartup<StartupThrowTypeLoadException>().Build();
+            var engine = builder.UseServer(server).UseStartup<StartupThrowTypeLoadException>().Build();
             using (engine.Start())
             {
-                await AssertResponseContains(serverFactory.Application, "Message from the LoaderException</span>");
+                await AssertResponseContains(server.RequestDelegate, "Message from the LoaderException</span>");
             }
         }
 
@@ -90,13 +90,13 @@ namespace Microsoft.AspNet.Hosting
         public async Task IApplicationLifetimeRegisteredEvenWhenStartupCtorThrows_Fallback()
         {
             var builder = CreateWebHostBuilder();
-            var serverFactory = new TestServerFactory();
+            var server = new TestServer();
-            var engine = builder.UseServer(serverFactory).UseStartup<StartupCtorThrows>().Build();
+            var engine = builder.UseServer(server).UseStartup<StartupCtorThrows>().Build();
             using (engine.Start())
             {
-                var service = engine.ApplicationServices.GetService<IApplicationLifetime>();
+                var service = engine.ApplicationServices.GetServices<IApplicationLifetime>();
                 Assert.NotNull(service);
-                await AssertResponseContains(serverFactory.Application, "Exception from constructor");
+                await AssertResponseContains(server.RequestDelegate, "Exception from constructor");
             }
         }
 
@@ -104,11 +104,11 @@ namespace Microsoft.AspNet.Hosting
         public async Task StartupConfigureServicesThrows_Fallback()
         {
             var builder = CreateWebHostBuilder();
-            var serverFactory = new TestServerFactory();
+            var server = new TestServer();
-            var engine = builder.UseServer(serverFactory).UseStartup<StartupConfigureServicesThrows>().Build();
+            var engine = builder.UseServer(server).UseStartup<StartupConfigureServicesThrows>().Build();
             using (engine.Start())
             {
-                await AssertResponseContains(serverFactory.Application, "Exception from ConfigureServices");
+                await AssertResponseContains(server.RequestDelegate, "Exception from ConfigureServices");
             }
         }
 
@@ -116,11 +116,11 @@ namespace Microsoft.AspNet.Hosting
         public async Task StartupConfigureThrows_Fallback()
         {
             var builder = CreateWebHostBuilder();
-            var serverFactory = new TestServerFactory();
+            var server = new TestServer();
-            var engine = builder.UseServer(serverFactory).UseStartup<StartupConfigureServicesThrows>().Build();
+            var engine = builder.UseServer(server).UseStartup<StartupConfigureServicesThrows>().Build();
             using (engine.Start())
             {
-                await AssertResponseContains(serverFactory.Application, "Exception from Configure");
+                await AssertResponseContains(server.RequestDelegate, "Exception from Configure");
             }
         }
 
@@ -137,36 +137,29 @@ namespace Microsoft.AspNet.Hosting
             return new WebHostBuilder(config, captureStartupErrors: true);
         }
 
-        private async Task AssertResponseContains(Func<IFeatureCollection, Task> app, string expectedText)
+        private async Task AssertResponseContains(RequestDelegate app, string expectedText)
         {
             var httpContext = new DefaultHttpContext();
             httpContext.Response.Body = new MemoryStream();
-            await app(httpContext.Features);
+            await app(httpContext);
             httpContext.Response.Body.Seek(0, SeekOrigin.Begin);
             var bodyText = new StreamReader(httpContext.Response.Body).ReadToEnd();
             Assert.Contains(expectedText, bodyText);
         }
 
-        private class TestServerFactory : IServerFactory
+        private class TestServer : IServer
         {
-            public Func<IFeatureCollection, Task> Application { get; set; }
+            IFeatureCollection IServer.Features { get; }
+            public RequestDelegate RequestDelegate { get; private set; }
 
-            public IFeatureCollection Initialize(IConfiguration configuration)
+            public void Dispose()
             {
-                return new FeatureCollection();
+
             }
 
-            public IDisposable Start(IFeatureCollection serverFeatures, Func<IFeatureCollection, Task> application)
+            public void Start(RequestDelegate requestDelegate)
             {
-                Application = application;
+                RequestDelegate = requestDelegate;
-                return new Disposable();
-            }
-
-            private class Disposable : IDisposable
-            {
-                public void Dispose()
-                {
-                }
             }
         }
     }

test/Microsoft.AspNet.TestHost.Tests/ClientHandlerTests.cs

@@ -17,13 +17,13 @@ namespace Microsoft.AspNet.TestHost
 {
     public class ClientHandlerTests
     {
+        private IHttpContextFactory _httpContextFactory = new HttpContextFactory(new HttpContextAccessor());
+
         [Fact]
         public Task ExpectedKeysAreAvailable()
         {
-            var handler = new ClientHandler(env =>
+            var handler = new ClientHandler(context =>
             {
-                var context = new DefaultHttpContext((IFeatureCollection)env);
-
                 // TODO: Assert.True(context.RequestAborted.CanBeCanceled);
                 Assert.Equal("HTTP/1.1", context.Request.Protocol);
                 Assert.Equal("GET", context.Request.Method);
@@ -40,7 +40,7 @@ namespace Microsoft.AspNet.TestHost
                 Assert.Equal("example.com", context.Request.Host.Value);
 
                 return Task.FromResult(0);
-            }, new PathString("/A/Path/"));
+            }, new PathString("/A/Path/"), _httpContextFactory);
             var httpClient = new HttpClient(handler);
             return httpClient.GetAsync("https://example.com/A/Path/and/file.txt?and=query");
         }
@@ -48,14 +48,13 @@ namespace Microsoft.AspNet.TestHost
         [Fact]
         public Task SingleSlashNotMovedToPathBase()
         {
-            var handler = new ClientHandler(env =>
+            var handler = new ClientHandler(context =>
             {
-                var context = new DefaultHttpContext((IFeatureCollection)env);
                 Assert.Equal("", context.Request.PathBase.Value);
                 Assert.Equal("/", context.Request.Path.Value);
 
                 return Task.FromResult(0);
-            }, new PathString(""));
+            }, new PathString(""), _httpContextFactory);
             var httpClient = new HttpClient(handler);
             return httpClient.GetAsync("https://example.com/");
         }
@@ -64,15 +63,14 @@ namespace Microsoft.AspNet.TestHost
         public async Task ResubmitRequestWorks()
         {
             int requestCount = 1;
-            var handler = new ClientHandler(env =>
+            var handler = new ClientHandler(context =>
             {
-                var context = new DefaultHttpContext((IFeatureCollection)env);
                 int read = context.Request.Body.Read(new byte[100], 0, 100);
                 Assert.Equal(11, read);
 
                 context.Response.Headers["TestHeader"] = "TestValue:" + requestCount++;
                 return Task.FromResult(0);
-            }, PathString.Empty);
+            }, PathString.Empty, _httpContextFactory);
 
             HttpMessageInvoker invoker = new HttpMessageInvoker(handler);
             HttpRequestMessage message = new HttpRequestMessage(HttpMethod.Post, "https://example.com/");
@@ -88,13 +86,11 @@ namespace Microsoft.AspNet.TestHost
         [Fact]
         public async Task MiddlewareOnlySetsHeaders()
         {
-            var handler = new ClientHandler(env =>
+            var handler = new ClientHandler(context =>
             {
-                var context = new DefaultHttpContext((IFeatureCollection)env);
-
                 context.Response.Headers["TestHeader"] = "TestValue";
                 return Task.FromResult(0);
-            }, PathString.Empty);
+            }, PathString.Empty, _httpContextFactory);
             var httpClient = new HttpClient(handler);
             HttpResponseMessage response = await httpClient.GetAsync("https://example.com/");
             Assert.Equal("TestValue", response.Headers.GetValues("TestHeader").First());
@@ -104,11 +100,11 @@ namespace Microsoft.AspNet.TestHost
         public async Task BlockingMiddlewareShouldNotBlockClient()
         {
             ManualResetEvent block = new ManualResetEvent(false);
-            var handler = new ClientHandler(env =>
+            var handler = new ClientHandler(context =>
             {
                 block.WaitOne();
                 return Task.FromResult(0);
-            }, PathString.Empty);
+            }, PathString.Empty, _httpContextFactory);
             var httpClient = new HttpClient(handler);
             Task<HttpResponseMessage> task = httpClient.GetAsync("https://example.com/");
             Assert.False(task.IsCompleted);
@@ -121,14 +117,13 @@ namespace Microsoft.AspNet.TestHost
         public async Task HeadersAvailableBeforeBodyFinished()
         {
             ManualResetEvent block = new ManualResetEvent(false);
-            var handler = new ClientHandler(async env =>
+            var handler = new ClientHandler(async context =>
             {
-                var context = new DefaultHttpContext((IFeatureCollection)env);
                 context.Response.Headers["TestHeader"] = "TestValue";
                 await context.Response.WriteAsync("BodyStarted,");
                 block.WaitOne();
                 await context.Response.WriteAsync("BodyFinished");
-            }, PathString.Empty);
+            }, PathString.Empty, _httpContextFactory);
             var httpClient = new HttpClient(handler);
             HttpResponseMessage response = await httpClient.GetAsync("https://example.com/",
                 HttpCompletionOption.ResponseHeadersRead);
@@ -141,14 +136,13 @@ namespace Microsoft.AspNet.TestHost
         public async Task FlushSendsHeaders()
         {
             ManualResetEvent block = new ManualResetEvent(false);
-            var handler = new ClientHandler(async env =>
+            var handler = new ClientHandler(async context =>
             {
-                var context = new DefaultHttpContext((IFeatureCollection)env);
                 context.Response.Headers["TestHeader"] = "TestValue";
                 context.Response.Body.Flush();
                 block.WaitOne();
                 await context.Response.WriteAsync("BodyFinished");
-            }, PathString.Empty);
+            }, PathString.Empty, _httpContextFactory);
             var httpClient = new HttpClient(handler);
             HttpResponseMessage response = await httpClient.GetAsync("https://example.com/",
                 HttpCompletionOption.ResponseHeadersRead);
@@ -161,14 +155,13 @@ namespace Microsoft.AspNet.TestHost
         public async Task ClientDisposalCloses()
         {
             ManualResetEvent block = new ManualResetEvent(false);
-            var handler = new ClientHandler(env =>
+            var handler = new ClientHandler(context =>
             {
-                var context = new DefaultHttpContext((IFeatureCollection)env);
                 context.Response.Headers["TestHeader"] = "TestValue";
                 context.Response.Body.Flush();
                 block.WaitOne();
                 return Task.FromResult(0);
-            }, PathString.Empty);
+            }, PathString.Empty, _httpContextFactory);
             var httpClient = new HttpClient(handler);
             HttpResponseMessage response = await httpClient.GetAsync("https://example.com/",
                 HttpCompletionOption.ResponseHeadersRead);
@@ -187,14 +180,13 @@ namespace Microsoft.AspNet.TestHost
         public async Task ClientCancellationAborts()
         {
             ManualResetEvent block = new ManualResetEvent(false);
-            var handler = new ClientHandler(env =>
+            var handler = new ClientHandler(context =>
             {
-                var context = new DefaultHttpContext((IFeatureCollection)env);
                 context.Response.Headers["TestHeader"] = "TestValue";
                 context.Response.Body.Flush();
                 block.WaitOne();
                 return Task.FromResult(0);
-            }, PathString.Empty);
+            }, PathString.Empty, _httpContextFactory);
             var httpClient = new HttpClient(handler);
             HttpResponseMessage response = await httpClient.GetAsync("https://example.com/",
                 HttpCompletionOption.ResponseHeadersRead);
@@ -213,10 +205,10 @@ namespace Microsoft.AspNet.TestHost
         [Fact]
         public Task ExceptionBeforeFirstWriteIsReported()
         {
-            var handler = new ClientHandler(env =>
+            var handler = new ClientHandler(context =>
             {
                 throw new InvalidOperationException("Test Exception");
-            }, PathString.Empty);
+            }, PathString.Empty, _httpContextFactory);
             var httpClient = new HttpClient(handler);
             return Assert.ThrowsAsync<InvalidOperationException>(() => httpClient.GetAsync("https://example.com/",
                 HttpCompletionOption.ResponseHeadersRead));
@@ -227,14 +219,13 @@ namespace Microsoft.AspNet.TestHost
         public async Task ExceptionAfterFirstWriteIsReported()
         {
             ManualResetEvent block = new ManualResetEvent(false);
-            var handler = new ClientHandler(async env =>
+            var handler = new ClientHandler(async context =>
             {
-                var context = new DefaultHttpContext((IFeatureCollection)env);
                 context.Response.Headers["TestHeader"] = "TestValue";
                 await context.Response.WriteAsync("BodyStarted");
                 block.WaitOne();
                 throw new InvalidOperationException("Test Exception");
-            }, PathString.Empty);
+            }, PathString.Empty, _httpContextFactory);
             var httpClient = new HttpClient(handler);
             HttpResponseMessage response = await httpClient.GetAsync("https://example.com/",
                 HttpCompletionOption.ResponseHeadersRead);