Use TaskCache class from Microsoft.Extensions.TaskCache.Sources (#361)

Instead of Task.FromResult(0)

src/Microsoft.AspNetCore.Routing/Internal/TaskCache.cs

@@ -1,16 +0,0 @@
-// 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.Threading.Tasks;
-
-namespace Microsoft.AspNetCore.Routing.Internal
-{
-    public static class TaskCache
-    {
-#if NETSTANDARD1_3
-        public static readonly Task CompletedTask = Task.CompletedTask;
-#else
-        public static readonly Task CompletedTask = Task.FromResult(0);
-#endif
-    }
-}

src/Microsoft.AspNetCore.Routing/RouteBase.cs

@@ -10,6 +10,7 @@ using Microsoft.AspNetCore.Routing.Internal;
 using Microsoft.AspNetCore.Routing.Logging;
 using Microsoft.AspNetCore.Routing.Template;
 using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Internal;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.ObjectPool;
 

src/Microsoft.AspNetCore.Routing/RouteHandler.cs

@@ -3,7 +3,7 @@
 
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Http;
-using Microsoft.AspNetCore.Routing.Internal;
+using Microsoft.Extensions.Internal;
 
 namespace Microsoft.AspNetCore.Routing
 {

src/Microsoft.AspNetCore.Routing/project.json

@@ -36,6 +36,10 @@
     "Microsoft.Extensions.PropertyHelper.Sources": {
       "type": "build",
       "version": "1.1.0-*"
+    },
+    "Microsoft.Extensions.TaskCache.Sources": {
+      "version": "1.1.0-*",
+      "type": "build"
     }
   },
   "frameworks": {

test/Microsoft.AspNetCore.Routing.Tests/RoutingBuilderExtensionsTest.cs

@@ -6,7 +6,6 @@ using System.Threading.Tasks;
 using Microsoft.AspNetCore.Builder.Internal;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Routing;
-using Microsoft.AspNetCore.Routing.Internal;
 using Microsoft.Extensions.DependencyInjection;
 using Moq;
 using Xunit;
@@ -60,7 +59,7 @@ namespace Microsoft.AspNetCore.Builder
             var router = new Mock<IRouter>(MockBehavior.Strict);
             router
                 .Setup(r => r.RouteAsync(It.IsAny<RouteContext>()))
-                .Returns(TaskCache.CompletedTask)
+                .Returns(Task.FromResult(0))
                 .Verifiable();
 
             app.UseRouter(router.Object);
@@ -85,7 +84,7 @@ namespace Microsoft.AspNetCore.Builder
             var router = new Mock<IRouter>(MockBehavior.Strict);
             router
                 .Setup(r => r.RouteAsync(It.IsAny<RouteContext>()))
-                .Returns(TaskCache.CompletedTask)
+                .Returns(Task.FromResult(0))
                 .Verifiable();
 
             app.UseRouter(b =>

test/Microsoft.AspNetCore.Routing.Tests/Tree/TreeRouterTest.cs

@@ -9,6 +9,7 @@ using System.Threading.Tasks;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Routing.Internal;
 using Microsoft.AspNetCore.Routing.Template;
+using Microsoft.Extensions.Internal;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Logging.Testing;
 using Microsoft.Extensions.ObjectPool;
@@ -1531,7 +1532,7 @@ namespace Microsoft.AspNetCore.Routing.Tree
                     nestedRouters = new List<IRouter>(c.RouteData.Routers);
                     c.Handler = null; // Not a match
                 })
-                .Returns(TaskCache.CompletedTask);
+                .Returns(Task.FromResult(0));
 
             var builder = CreateBuilder();
             MapInboundEntry(builder, "api/Store", handler: next.Object);
@@ -1568,7 +1569,7 @@ namespace Microsoft.AspNetCore.Routing.Tree
                     nestedRouters = new List<IRouter>(c.RouteData.Routers);
                     c.Handler = null; // Not a match
                 })
-                .Returns(TaskCache.CompletedTask);
+                .Returns(Task.FromResult(0));
 
             var builder = CreateBuilder();
             MapInboundEntry(builder, "api/Store", handler: next.Object);
@@ -1612,7 +1613,7 @@ namespace Microsoft.AspNetCore.Routing.Tree
                     nestedRouters = new List<IRouter>(c.RouteData.Routers);
                     throw new Exception();
                 })
-                .Returns(TaskCache.CompletedTask);
+                .Returns(Task.FromResult(0));
 
             var builder = CreateBuilder();
             MapInboundEntry(builder, "api/Store", handler: next.Object);