Added support for net451 and netstandard1.3

- Replaced Task.CompletedTask with TaskCache.CompletedTask
- Updated tests and src

src/Microsoft.AspNetCore.SignalR/DefaultHubLifetimeManager.cs

@@ -7,6 +7,7 @@ using System.Linq;
 using System.Threading.Tasks;
 using Channels;
 using Microsoft.AspNetCore.Sockets;
+using Microsoft.Extensions.Internal;
 
 namespace Microsoft.AspNetCore.SignalR
 {
@@ -29,7 +30,7 @@ namespace Microsoft.AspNetCore.SignalR
                 groups.Add(groupName);
             }
 
-            return Task.CompletedTask;
+            return TaskCache.CompletedTask;
         }
 
         public override Task RemoveGroupAsync(Connection connection, string groupName)
@@ -41,7 +42,7 @@ namespace Microsoft.AspNetCore.SignalR
                 groups.Remove(groupName);
             }
 
-            return Task.CompletedTask;
+            return TaskCache.CompletedTask;
         }
 
         public override Task InvokeAllAsync(string methodName, object[] args)
@@ -109,13 +110,13 @@ namespace Microsoft.AspNetCore.SignalR
         public override Task OnConnectedAsync(Connection connection)
         {
             _connections.Add(connection);
-            return Task.CompletedTask;
+            return TaskCache.CompletedTask;
         }
 
         public override Task OnDisconnectedAsync(Connection connection)
         {
             _connections.Remove(connection);
-            return Task.CompletedTask;
+            return TaskCache.CompletedTask;
         }
     }
 

src/Microsoft.AspNetCore.SignalR/Hub.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Threading.Tasks;
+using Microsoft.Extensions.Internal;
 
 namespace Microsoft.AspNetCore.SignalR
 {
@@ -62,12 +63,12 @@ namespace Microsoft.AspNetCore.SignalR
 
         public virtual Task OnConnectedAsync()
         {
-            return Task.CompletedTask;
+            return TaskCache.CompletedTask;
         }
 
         public virtual Task OnDisconnectedAsync()
         {
-            return Task.CompletedTask;
+            return TaskCache.CompletedTask;
         }
 
         protected virtual void Dispose(bool disposing)

src/Microsoft.AspNetCore.SignalR/HubEndPoint.cs

@@ -30,6 +30,7 @@ namespace Microsoft.AspNetCore.SignalR
         private readonly Dictionary<string, Func<Connection, InvocationDescriptor, Task<InvocationResultDescriptor>>> _callbacks
             = new Dictionary<string, Func<Connection, InvocationDescriptor, Task<InvocationResultDescriptor>>>(StringComparer.OrdinalIgnoreCase);
         private readonly Dictionary<string, Type[]> _paramTypes = new Dictionary<string, Type[]>();
+        private static object[] EmptyArray = new object[0];
 
         private readonly HubLifetimeManager<THub> _lifetimeManager;
         private readonly IHubContext<THub, TClient> _hubContext;
@@ -183,7 +184,7 @@ namespace Microsoft.AspNetCore.SignalR
 
                         try
                         {
-                            var arguments = invocationDescriptor.Arguments ?? Array.Empty<object>();
+                            var arguments = invocationDescriptor.Arguments ?? EmptyArray;
 
                             var args = arguments
                                 .Zip(parameters, (a, p) => Convert.ChangeType(a, p.ParameterType))

src/Microsoft.AspNetCore.SignalR/project.json

@@ -25,12 +25,16 @@
     "Microsoft.AspNetCore.Sockets": {
       "target": "project"
     },
+    "Microsoft.Extensions.TaskCache.Sources": {
+      "version": "1.1.0-*",
+      "type": "build"
+    },
     "NETStandard.Library": "1.6.1-*",
     "Newtonsoft.Json": "9.0.1"
   },
 
   "frameworks": {
-    "netstandard1.6": {
-    }
+    "netstandard1.3": {},
+    "net451": {}
   }
 }

src/Microsoft.AspNetCore.Sockets/WebSockets.cs

@@ -27,7 +27,6 @@ namespace Microsoft.AspNetCore.Sockets
         {
             if (!context.WebSockets.IsWebSocketRequest)
             {
-                await Task.CompletedTask;
                 return;
             }
 

src/Microsoft.AspNetCore.Sockets/project.json

@@ -30,6 +30,6 @@
   },
   "frameworks": {
     "netstandard1.3": {},
-    "net46": {}
+    "net451": {}
   }
 }

src/Microsoft.Extensions.WebSockets.Internal/IWebSocketConnection.cs

@@ -4,6 +4,7 @@
 using System;
 using System.Threading;
 using System.Threading.Tasks;
+using Microsoft.Extensions.Internal;
 
 namespace Microsoft.Extensions.WebSockets.Internal
 {
@@ -129,7 +130,7 @@ namespace Microsoft.Extensions.WebSockets.Internal
             connection.ExecuteAsync((frame, _) =>
             {
                 messageHandler(frame);
-                return Task.CompletedTask;
+                return TaskCache.CompletedTask;
             }, null);
 
         /// <summary>
@@ -143,7 +144,7 @@ namespace Microsoft.Extensions.WebSockets.Internal
             connection.ExecuteAsync((frame, s) =>
             {
                 messageHandler(frame, s);
-                return Task.CompletedTask;
+                return TaskCache.CompletedTask;
             }, state);
 
         /// <summary>

src/Microsoft.Extensions.WebSockets.Internal/project.json

@@ -25,10 +25,15 @@
   "dependencies": {
     "Channels": "0.2.0-beta-*",
     "Channels.Text.Primitives": "0.2.0-beta-*",
+    "Microsoft.Extensions.TaskCache.Sources": {
+      "version": "1.1.0-*",
+      "type": "build"
+    },
     "NETStandard.Library": "1.6.1-*"
   },
 
   "frameworks": {
-    "netstandard1.3": {}
+    "netstandard1.3": {},
+    "net451": {}
   }
 }

test/Microsoft.AspNetCore.Sockets.Tests/project.json

@@ -20,7 +20,7 @@
         }
       }
     },
-    "net46": {}
+    "net451": {}
   },
   "testRunner": "xunit"
 }

test/Microsoft.AspNetCore.WebSockets.Internal.ConformanceTest/project.json

@@ -10,18 +10,19 @@
     "Microsoft.Extensions.Logging": "1.1.0-*",
     "Microsoft.Extensions.Logging.Console": "1.1.0-*",
     "Microsoft.Extensions.PlatformAbstractions": "1.1.0-*",
-    "System.Diagnostics.FileVersionInfo": "4.3.0-*",
     "xunit": "2.2.0-*"
   },
   "testRunner": "xunit",
   "frameworks": {
     "netcoreapp1.1": {
       "dependencies": {
+        "System.Diagnostics.FileVersionInfo": "4.3.0-*",
         "Microsoft.NETCore.App": {
           "version": "1.1.0-*",
           "type": "platform"
         }
       }
-    }
+    },
+    "net451": { }
   }
 }

test/Microsoft.Extensions.WebSockets.Internal.Tests/WebSocketConnectionTests.ConnectionLifecycle.cs

@@ -6,6 +6,7 @@ using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 using Channels;
+using Microsoft.Extensions.Internal;
 using Xunit;
 
 namespace Microsoft.Extensions.WebSockets.Internal.Tests
@@ -22,7 +23,7 @@ namespace Microsoft.Extensions.WebSockets.Internal.Tests
                     var client = pair.ClientSocket.ExecuteAsync(_ =>
                     {
                         Assert.False(true, "did not expect the client to receive any frames!");
-                        return Task.CompletedTask;
+                        return TaskCache.CompletedTask;
                     });
 
                     // Send Frames

test/Microsoft.Extensions.WebSockets.Internal.Tests/WebSocketConnectionTests.SendAsync.cs

@@ -5,6 +5,7 @@ using System;
 using System.Text;
 using System.Threading.Tasks;
 using Channels;
+using Microsoft.Extensions.Internal;
 using Xunit;
 
 namespace Microsoft.Extensions.WebSockets.Internal.Tests
@@ -182,7 +183,7 @@ namespace Microsoft.Extensions.WebSockets.Internal.Tests
                         executeTask = connection.ExecuteAsync(f =>
                         {
                             Assert.False(true, "Did not expect to receive any messages");
-                            return Task.CompletedTask;
+                            return TaskCache.CompletedTask;
                         });
                         await producer(connection).OrTimeout();
                         inbound.CompleteWriter();

test/Microsoft.Extensions.WebSockets.Internal.Tests/project.json

@@ -5,6 +5,10 @@
 
   "dependencies": {
     "dotnet-test-xunit": "2.2.0-*",
+    "Microsoft.Extensions.TaskCache.Sources": {
+      "version": "1.1.0-*",
+      "type": "build"
+    },
     "Microsoft.Extensions.WebSockets.Internal": "0.1.0-*",
     "xunit": "2.2.0-*"
   },
@@ -22,7 +26,7 @@
         "portable-net451+win8"
       ]
     },
-    "net46": {
+    "net451": {
       "dependencies": {
         "xunit.runner.console": "2.1.0"
       }