Remove sync helpers

Author: HaoK

src/Microsoft.AspNet.Http.Abstractions/HttpResponse.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.IO;
+using System.Threading.Tasks;
 
 namespace Microsoft.AspNet.Http
 {
@@ -24,9 +25,9 @@ public abstract class HttpResponse
 
         public abstract bool HasStarted { get; }
 
-        public abstract void OnResponseStarting(Action<object> callback, object state);
+        public abstract void OnResponseStarting(Func<object, Task> callback, object state);
 
-        public abstract void OnResponseCompleted(Action<object> callback, object state);
+        public abstract void OnResponseCompleted(Func<object, Task> callback, object state);
 
         public virtual void Redirect(string location)
         {

src/Microsoft.AspNet.Http.Features/Authentication/ChallengeContext.cs

@@ -8,6 +8,10 @@ namespace Microsoft.AspNet.Http.Features.Authentication
 {
     public class ChallengeContext
     {
+        public ChallengeContext(string authenticationScheme) : this(authenticationScheme, properties: null, behavior: ChallengeBehavior.Automatic)
+        {
+        }
+
         public ChallengeContext(string authenticationScheme, IDictionary<string, string> properties, ChallengeBehavior behavior)
         {
             AuthenticationScheme = authenticationScheme;

src/Microsoft.AspNet.Http.Features/IHttpResponseFeature.cs

@@ -4,6 +4,7 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+using System.Threading.Tasks;
 
 namespace Microsoft.AspNet.Http.Features
 {
@@ -14,7 +15,7 @@ public interface IHttpResponseFeature
         IDictionary<string, string[]> Headers { get; set; }
         Stream Body { get; set; }
         bool HasStarted { get; }
-        void OnResponseStarting(Action<object> callback, object state);
-        void OnResponseCompleted(Action<object> callback, object state);
+        void OnResponseStarting(Func<object, Task> callback, object state);
+        void OnResponseCompleted(Func<object, Task> callback, object state);
     }
 }

src/Microsoft.AspNet.Http/DefaultHttpResponse.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.IO;
+using System.Threading.Tasks;
 using Microsoft.AspNet.FeatureModel;
 using Microsoft.AspNet.Http.Features;
 using Microsoft.AspNet.Http.Features.Internal;
@@ -94,12 +95,12 @@ public override bool HasStarted
             get { return HttpResponseFeature.HasStarted; }
         }
 
-        public override void OnResponseStarting(Action<object> callback, object state)
+        public override void OnResponseStarting(Func<object, Task> callback, object state)
         {
             HttpResponseFeature.OnResponseStarting(callback, state);
         }
 
-        public override void OnResponseCompleted(Action<object> callback, object state)
+        public override void OnResponseCompleted(Func<object, Task> callback, object state)
         {
             HttpResponseFeature.OnResponseCompleted(callback, state);
         }

src/Microsoft.AspNet.Http/Features/HttpResponseFeature.cs

@@ -4,6 +4,7 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+using System.Threading.Tasks;
 
 namespace Microsoft.AspNet.Http.Features.Internal
 {
@@ -29,14 +30,14 @@ public bool HasStarted
             get { return false; }
         }
 
-        public void OnResponseStarting(Action<object> callback, object state)
+        public void OnResponseStarting(Func<object, Task> callback, object state)
         {
-            throw new NotSupportedException();
+            throw new NotImplementedException();
         }
 
-        public void OnResponseCompleted(Action<object> callback, object state)
+        public void OnResponseCompleted(Func<object, Task> callback, object state)
         {
-            throw new NotSupportedException();
+            throw new NotImplementedException();
         }
     }
 }

src/Microsoft.AspNet.Owin/OwinEnvironment.cs

@@ -61,7 +61,7 @@ public OwinEnvironment(HttpContext context)
                 { OwinConstants.ResponseReasonPhrase, new FeatureMap<IHttpResponseFeature>(feature => feature.ReasonPhrase, (feature, value) => feature.ReasonPhrase = Convert.ToString(value)) },
                 { OwinConstants.ResponseHeaders, new FeatureMap<IHttpResponseFeature>(feature => feature.Headers, (feature, value) => feature.Headers = (IDictionary<string, string[]>)value) },
                 { OwinConstants.ResponseBody, new FeatureMap<IHttpResponseFeature>(feature => feature.Body, () => Stream.Null, (feature, value) => feature.Body = (Stream)value) },
-                { OwinConstants.CommonKeys.OnSendingHeaders, new FeatureMap<IHttpResponseFeature>(feature => new Action<Action<object>, object>(feature.OnResponseStarting)) },
+                { OwinConstants.CommonKeys.OnSendingHeaders, new FeatureMap<IHttpResponseFeature>(feature => new Action<Func<object, Task>, object>(feature.OnResponseStarting)) },
 
                 { OwinConstants.CommonKeys.LocalPort, new FeatureMap<IHttpConnectionFeature>(feature => feature.LocalPort.ToString(CultureInfo.InvariantCulture),
                     (feature, value) => feature.LocalPort = Convert.ToInt32(value, CultureInfo.InvariantCulture)) },

src/Microsoft.AspNet.Owin/OwinFeatureCollection.cs

@@ -147,17 +147,17 @@ bool IHttpResponseFeature.HasStarted
             get { return _headersSent; }
         }
 
-        void IHttpResponseFeature.OnResponseStarting(Action<object> callback, object state)
+        void IHttpResponseFeature.OnResponseStarting(Func<object, Task> callback, object state)
         {
-            var register = Prop<Action<Action<object>, object>>(OwinConstants.CommonKeys.OnSendingHeaders);
+            var register = Prop<Action<Func<object, Task>, object>>(OwinConstants.CommonKeys.OnSendingHeaders);
             if (register == null)
             {
                 throw new NotSupportedException(OwinConstants.CommonKeys.OnSendingHeaders);
             }
             register(callback, state);
         }
 
-        void IHttpResponseFeature.OnResponseCompleted(Action<object> callback, object state)
+        void IHttpResponseFeature.OnResponseCompleted(Func<object, Task> callback, object state)
         {
             throw new NotSupportedException();
         }