Return EmptyResult for actions with void or Task return type

src/Microsoft.AspNet.Mvc.Core/ControllerActionInvoker.cs

@@ -108,11 +108,7 @@ internal static IActionResult CreateActionResult([NotNull] Type declaredReturnTy
             if (declaredReturnType == typeof(void) ||
                 declaredReturnType == typeof(Task))
             {
-                return new ObjectResult(null)
-                {
-                    // Treat the declared type as void, which is the unwrapped type for Task.
-                    DeclaredType = typeof(void)
-                };
+                return new EmptyResult();
             }
 
             // Unwrap potential Task<T> types.

test/Microsoft.AspNet.Mvc.Core.Test/ControllerActionInvokerTest.cs

@@ -1920,17 +1920,13 @@ public void CreateActionResult_NullActionResultReturnValueThrows()
         [Theory]
         [InlineData(typeof(void))]
         [InlineData(typeof(Task))]
-        public void CreateActionResult_Types_ReturnsObjectResultForTaskAndVoidReturnTypes(Type type)
+        public void CreateActionResult_Types_ReturnsEmptyResultForTaskAndVoidReturnTypes(Type type)
         {
             // Arrange & Act
             var result = ControllerActionInvoker.CreateActionResult(type, null);
 
             // Assert
-            var objectResult = Assert.IsType<ObjectResult>(result);
-
-            // Since we unwrap the Task type to void, the expected type will always be void.
-            Assert.Equal(typeof(void), objectResult.DeclaredType);
-            Assert.Null(objectResult.Value);
+            Assert.IsType<EmptyResult>(result);
         }
 
         public static IEnumerable<object[]> CreateActionResult_ReturnsObjectContentResultData

test/Microsoft.AspNet.Mvc.FunctionalTests/BasicTests.cs

@@ -129,7 +129,7 @@ public async Task CanReturn_ResultsWithoutContent()
         }
 
         [Fact]
-        public async Task ReturningTaskFromAction_ProducesNoContentResult()
+        public async Task ReturningTaskFromAction_ProducesEmptyResult()
         {
             // Arrange
             var server = TestHelper.CreateServer(_app, SiteName, _configureServices);
@@ -139,8 +139,9 @@ public async Task ReturningTaskFromAction_ProducesNoContentResult()
             var response = await client.GetAsync("http://localhost/Home/ActionReturningTask");
 
             // Assert
-            Assert.Equal(HttpStatusCode.NoContent, response.StatusCode);
+            Assert.Equal(HttpStatusCode.OK, response.StatusCode);
             Assert.Equal("Hello, World!", Assert.Single(response.Headers.GetValues("Message")));
+            Assert.Empty(await response.Content.ReadAsStringAsync());
         }
 
         [Fact]

test/Microsoft.AspNet.Mvc.FunctionalTests/OutputFormatterTest.cs

@@ -60,7 +60,7 @@ public async Task JsonOutputFormatter_ForNonStringValue_GetsSelected(string acti
         [Theory]
         [InlineData("ReturnTask")]
         [InlineData("ReturnVoid")]
-        public async Task NoContentFormatter_ForVoidAndTaskReturnType_GetsSelectedAndWritesResponse(string actionName)
+        public async Task NoContentFormatter_ForVoidAndTaskReturnType_DoesNotRun(string actionName)
         {
             // Arrange
             var server = TestHelper.CreateServer(_app, SiteName, _configureServices);
@@ -74,7 +74,7 @@ public async Task NoContentFormatter_ForVoidAndTaskReturnType_GetsSelectedAndWri
             var body = await response.Content.ReadAsStringAsync();
             // Response body is empty instead of null.
             Assert.Empty(body);
-            Assert.Equal(HttpStatusCode.NoContent, response.StatusCode);
+            Assert.Equal(HttpStatusCode.OK, response.StatusCode);
             Assert.Equal(0, response.Content.Headers.ContentLength);
         }