WIP - First stab at creating a BodyDelegate type

src/Nancy.Hosting.Aspnet/NancyHandler.cs

@@ -37,7 +37,7 @@ public async Task ProcessRequest(HttpContextBase httpContext)
 
             using(var nancyContext = await this.engine.HandleRequest(request).ConfigureAwait(false))
             {
-                SetNancyResponseToHttpResponse(httpContext, nancyContext.Response);
+                await SetNancyResponseToHttpResponse(httpContext, nancyContext.Response);
             }
         }
 
@@ -118,7 +118,7 @@ private static long GetExpectedRequestLength(IDictionary<string, IEnumerable<str
             return contentLength;
         }
 
-        public static void SetNancyResponseToHttpResponse(HttpContextBase context, Response response)
+        public static Task SetNancyResponseToHttpResponse(HttpContextBase context, Response response)
         {
             SetHttpResponseHeaders(context, response);
 
@@ -139,7 +139,7 @@ public static void SetNancyResponseToHttpResponse(HttpContextBase context, Respo
                 context.Response.StatusDescription = response.ReasonPhrase;
             }
 
-            response.Contents.Invoke(new NancyResponseStream(context.Response));
+            return response.Contents.Body.Invoke(new NancyResponseStream(context.Response));
         }
 
         private static bool IsOutputBufferDisabled()

src/Nancy.MSBuild/BodyDelegate.cs

@@ -0,0 +1,31 @@
+namespace Nancy
+{
+    using System;
+    using System.IO;
+    using System.Threading.Tasks;
+
+    public class BodyDelegate
+    {
+        public Func<Stream, Task> Body { get; set; }
+
+        public static implicit operator BodyDelegate(Func<Stream, Task> body)
+        {
+            return new BodyDelegate { Body = body };
+        }
+
+        public static implicit operator BodyDelegate(Action<Stream> body)
+        {
+            return new BodyDelegate { Body = Wrap(body) };
+        }
+
+        private static Func<Stream, Task> Wrap(Action<Stream> body)
+        {
+            return s =>
+            {
+                body.Invoke(s);
+
+                return Task.FromResult(new object());
+            };
+        }
+    }
+}

src/Nancy.MSBuild/Nancy.csproj

@@ -356,15 +356,15 @@
     <Compile Include="..\Nancy\Helpers\ExceptionExtensions.cs">
       <Link>Helpers\ExceptionExtensions.cs</Link>
     </Compile>
-    <Compile Include="..\Nancy\HttpLink.cs">
-      <Link>HttpLink.cs</Link>
-    </Compile>
-    <Compile Include="..\Nancy\HttpLinkBuilder.cs">
-      <Link>HttpLinkBuilder.cs</Link>
-    </Compile>
-    <Compile Include="..\Nancy\HttpLinkRelation.cs">
-      <Link>HttpLinkRelation.cs</Link>
-    </Compile>
+    <Compile Include="..\Nancy\HttpLink.cs">
+      <Link>HttpLink.cs</Link>
+    </Compile>
+    <Compile Include="..\Nancy\HttpLinkBuilder.cs">
+      <Link>HttpLinkBuilder.cs</Link>
+    </Compile>
+    <Compile Include="..\Nancy\HttpLinkRelation.cs">
+      <Link>HttpLinkRelation.cs</Link>
+    </Compile>
     <Compile Include="..\Nancy\IAssemblyCatalog.cs">
       <Link>IAssemblyCatalog.cs</Link>
     </Compile>
@@ -1376,6 +1376,7 @@
     <Compile Include="..\Nancy\Routing\Route.cs">
       <Link>Routing\Route.cs</Link>
     </Compile>
+    <Compile Include="BodyDelegate.cs" />
   </ItemGroup>
   <ItemGroup>
     <EmbeddedResource Include="..\Nancy\Diagnostics\Views\Dashboard.sshtml">

src/Nancy/Bootstrapper/NancyBootstrapperBase.cs

@@ -3,6 +3,7 @@
     using System;
     using System.Collections.Generic;
     using System.Diagnostics.CodeAnalysis;
+    using System.IO;
     using System.Linq;
 
     using Nancy.Configuration;
@@ -313,7 +314,7 @@ public void Initialise()
                                 {
                                     ContentType = "image/vnd.microsoft.icon",
                                     StatusCode = HttpStatusCode.OK,
-                                    Contents = s => s.Write(this.FavIcon, 0, this.FavIcon.Length)
+                                    Contents = (Action<Stream>)(s => s.Write(this.FavIcon, 0, this.FavIcon.Length))
                                 };
 
                             response.Headers["Cache-Control"] = "public, max-age=604800, must-revalidate";

src/Nancy/Diagnostics/DiagnosticsViewRenderer.cs

@@ -73,7 +73,7 @@ private static Stream GetBodyStream(string name)
 
             var stream = new MemoryStream();
 
-            view.Contents.Invoke(stream);
+            view.Contents.Body.Invoke(stream).Wait();
             stream.Position = 0;
             return stream;
         }

src/Nancy/ErrorHandling/DefaultStatusCodeHandler.cs

@@ -1,5 +1,6 @@
 namespace Nancy.ErrorHandling
 {
+    using System;
     using System.Collections.Generic;
     using System.IO;
     using System.Linq;
@@ -127,13 +128,13 @@ private void ModifyResponse(HttpStatusCode statusCode, NancyContext context, Def
             }
 
             context.Response.ContentType = "text/html";
-            context.Response.Contents = s =>
+            context.Response.Contents = (Action<Stream>)(s =>
             {
                 using (var writer = new StreamWriter(new UnclosableStreamWrapper(s), Encoding.UTF8))
                 {
                     writer.Write(contents);
                 }
-            };
+            });
         }
 
         private static string LoadResource(string filename)

src/Nancy/HeadResponse.cs

@@ -23,11 +23,11 @@ public class HeadResponse : Response
         public HeadResponse(Response response)
         {
             this.innerResponse = response;
-            this.Contents = stream =>
+            this.Contents = (Func<Stream, Task>)(async stream =>
             {
-                this.CheckAndSetContentLength(this.innerResponse);
+                await this.CheckAndSetContentLength(this.innerResponse);
                 GetStringContents(string.Empty)(stream);
-            };
+            });
             this.ContentType = response.ContentType;
             this.Headers = response.Headers;
             this.StatusCode = response.StatusCode;
@@ -48,7 +48,7 @@ public override Task PreExecute(NancyContext context)
             return this.innerResponse.PreExecute(context);
         }
 
-        private void CheckAndSetContentLength(Response response)
+        private async Task CheckAndSetContentLength(Response response)
         {
             if (this.Headers.ContainsKey(ContentLength))
             {
@@ -57,7 +57,7 @@ private void CheckAndSetContentLength(Response response)
 
             using (var nullStream = new NullStream())
             {
-                response.Contents.Invoke(nullStream);
+                await response.Contents.Body.Invoke(nullStream);
 
                 this.Headers[ContentLength] = nullStream.Length.ToString(CultureInfo.InvariantCulture);
             }

src/Nancy/Jsonp.cs

@@ -4,6 +4,7 @@
     using System.IO;
     using System.Linq;
     using System.Text;
+    using System.Threading.Tasks;
     using Nancy.Bootstrapper;
     using Nancy.Configuration;
     using Nancy.Json;
@@ -73,7 +74,7 @@ private static void PrepareJsonp(NancyContext context)
             // http://stackoverflow.com/questions/111302/best-content-type-to-serve-jsonp
             context.Response.ContentType = string.Concat("application/javascript", Encoding);
 
-            context.Response.Contents = stream =>
+            context.Response.Contents = (Func<Stream, Task>)(async stream =>
             {
                 // disposing of stream is handled elsewhere
                 var writer = new StreamWriter(stream)
@@ -82,9 +83,9 @@ private static void PrepareJsonp(NancyContext context)
                 };
 
                 writer.Write("{0}(", callback);
-                original(stream);
+                await original.Body.Invoke(stream);
                 writer.Write(");");
-            };
+            });
         }
     }
 }

src/Nancy/Owin/NancyMiddleware.cs

@@ -152,16 +152,15 @@ public static MidFunc UseNancy(NancyOptions options = null)
                         .ToArray();
                 }
 
-                nancyResponse.Contents(owinResponseBody);
+                using (context)
+                {
+                    return nancyResponse.Contents.Body.Invoke(owinResponseBody);
+                }
             }
             else
             {
                 return next(environment);
             }
-
-            context.Dispose();
-
-            return TaskHelpers.CompletedTask;
         }
 
         private static T Get<T>(IDictionary<string, object> env, string key)

src/Nancy/Response.cs

@@ -61,7 +61,7 @@ public string ContentType
         /// </summary>
         /// <value>An <see cref="Action{T}"/> delegate, containing the code that will render contents to the response stream.</value>
         /// <remarks>The host of Nancy will pass in the output stream after the response has been handed back to it by Nancy.</remarks>
-        public Action<Stream> Contents { get; set; }
+        public BodyDelegate Contents { get; set; }
 
         /// <summary>
         /// Gets the collection of HTTP response headers that should be sent back to the client.

src/Nancy/Responses/EmbeddedFileResponse.cs

@@ -7,6 +7,7 @@
     using System.Security.Cryptography;
     using System.Text;
     using System.Text.RegularExpressions;
+    using System.Threading.Tasks;
 
     /// <summary>
     /// Represent an HTML response with embeded file content.
@@ -42,17 +43,17 @@ public EmbeddedFileResponse(Assembly assembly, string resourcePath, string name)
                 content.Seek(0, SeekOrigin.Begin);
             }
 
-            this.Contents = stream =>
+            this.Contents = (Func<Stream, Task>)(async stream =>
             {
                 if (content != null)
                 {
-                    content.CopyTo(stream);
+                    await content.CopyToAsync(stream);
                 }
                 else
                 {
                     stream.Write(ErrorText, 0, ErrorText.Length);
                 }
-            };
+            });
         }
 
         private Stream GetResourceContent(Assembly assembly, string resourcePath, string name)

src/Nancy/Responses/MaterialisingResponse.cs

@@ -25,15 +25,16 @@ public class MaterialisingResponse : Response
         /// <returns>
         /// Task for completion/erroring
         /// </returns>
-        public override Task PreExecute(NancyContext context)
+        public override async Task PreExecute(NancyContext context)
         {
             using (var memoryStream = new MemoryStream())
             {
-                this.sourceResponse.Contents.Invoke(memoryStream);
+                await this.sourceResponse.Contents.Body.Invoke(memoryStream);
+
                 this.oldResponseOutput = memoryStream.ToArray();
             }
 
-            return base.PreExecute(context);
+            await base.PreExecute(context);
         }
 
         /// <summary>
@@ -49,18 +50,18 @@ public MaterialisingResponse(Response sourceResponse)
             this.StatusCode = sourceResponse.StatusCode;
             this.ReasonPhrase = sourceResponse.ReasonPhrase;
 
-            this.Contents = WriteContents;
+            this.Contents = (Func<Stream, Task>)WriteContents;
         }
 
-        private void WriteContents(Stream stream)
+        private async Task WriteContents(Stream stream)
         {
             if (this.oldResponseOutput == null)
             {
-                this.sourceResponse.Contents.Invoke(stream);
+                await this.sourceResponse.Contents.Body.Invoke(stream);
             }
             else
             {
-                stream.Write(this.oldResponseOutput, 0, this.oldResponseOutput.Length);
+                await stream.WriteAsync(this.oldResponseOutput, 0, this.oldResponseOutput.Length);
             }
         }
     }

src/Nancy/Responses/Negotiation/XmlProcessor.cs

@@ -2,7 +2,9 @@
 {
     using System;
     using System.Collections.Generic;
+    using System.IO;
     using System.Linq;
+    using System.Net.Mime;
 
     /// <summary>
     /// Processes the model for xml media types and extension.
@@ -83,13 +85,13 @@ private static Response CreateResponse(dynamic model, ISerializer serializer)
         {
             return new Response
             {
-                Contents = stream =>
+                Contents = (Action<Stream>)(stream =>
                 {
                     if (model != null)
                     {
                         serializer.Serialize("application/xml", model, stream);
                     }
-                },
+                }),
                 ContentType = "application/xml",
                 StatusCode = HttpStatusCode.OK
             };

src/Nancy/Responses/TextResponse.cs

@@ -1,6 +1,8 @@
 namespace Nancy.Responses
 {
+    using System;
     using System.Collections.Generic;
+    using System.IO;
     using System.Text;
 
     using Nancy.Cookies;
@@ -36,11 +38,11 @@ public TextResponse(string contents, string contentType = null, Encoding encodin
 
             if (contents != null)
             {
-                this.Contents = stream =>
+                this.Contents = (Action<Stream>)(stream =>
                 {
                     var data = encoding.GetBytes(contents);
                     stream.Write(data, 0, data.Length);
-                };
+                });
             }
         }
 
@@ -66,11 +68,11 @@ public TextResponse(HttpStatusCode statusCode = HttpStatusCode.OK, string conten
 
             if (contents != null)
             {
-                this.Contents = stream =>
+                this.Contents = (Action<Stream>)(stream =>
                 {
                     var data = encoding.GetBytes(contents);
                     stream.Write(data, 0, data.Length);
-                };
+                });
             }
 
             if (headers != null)