Fix #2414 Part 2 - Add [DefaultValue(...)] support to the invoker for

action parameters

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

@@ -3,6 +3,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.ComponentModel;
 using System.Linq;
 using System.Reflection;
 using System.Runtime.ExceptionServices;
@@ -125,9 +126,19 @@ namespace Microsoft.AspNet.Mvc
                     }
                     else
                     {
-                        value = parameterInfo.ParameterType.GetTypeInfo().IsValueType
-                            ? Activator.CreateInstance(parameterInfo.ParameterType)
-                            : null;
+                        var defaultValueAttribute = 
+                            parameterInfo.GetCustomAttribute<DefaultValueAttribute>(inherit: false);
+
+                        if (defaultValueAttribute?.Value == null)
+                        {
+                            value = parameterInfo.ParameterType.GetTypeInfo().IsValueType
+                                ? Activator.CreateInstance(parameterInfo.ParameterType)
+                                : null;
+                        }
+                        else
+                        {
+                            value = defaultValueAttribute.Value;
+                        }
                     }
                 }
 

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

@@ -193,6 +193,70 @@ namespace Microsoft.AspNet.Mvc.Core.Test
                                                 new Dictionary<string, object>() { { "input", inputString } }));
         }
 
+        [Fact]
+        public async Task ExecuteAsync_WithArgumentDictionary_DefaultValueAttributeUsed()
+        {
+            // Arrange
+            var syncMethod = new SyncMethod(_controller.EchoWithDefaultValue);
+
+            // Act
+            var result = await ControllerActionExecutor.ExecuteAsync(
+                syncMethod.GetMethodInfo(),
+                _controller,
+                new Dictionary<string, object>());
+
+            // Assert
+            Assert.Equal("hello", result);
+        }
+
+        [Fact]
+        public async Task ExecuteAsync_WithArgumentArray_DefaultValueAttributeIgnored()
+        {
+            // Arrange
+            var syncMethod = new SyncMethod(_controller.EchoWithDefaultValue);
+
+            // Act
+            var result = await ControllerActionExecutor.ExecuteAsync(
+                syncMethod.GetMethodInfo(),
+                _controller,
+                new object[] { null, });
+
+            // Assert
+            Assert.Null(result);
+        }
+
+        [Fact]
+        public async Task ExecuteAsync_WithArgumentDictionary_DefaultParameterValueUsed()
+        {
+            // Arrange
+            var syncMethod = new SyncMethod(_controller.EchoWithDefaultValueAndAttribute);
+
+            // Act
+            var result = await ControllerActionExecutor.ExecuteAsync(
+                syncMethod.GetMethodInfo(),
+                _controller,
+                new Dictionary<string, object>());
+
+            // Assert
+            Assert.Equal("world", result);
+        }
+
+        [Fact]
+        public async Task ExecuteAsync_WithArgumentDictionary_AnyValue_HasPrecedenceOverDefaults()
+        {
+            // Arrange
+            var syncMethod = new SyncMethod(_controller.EchoWithDefaultValueAndAttribute);
+
+            // Act
+            var result = await ControllerActionExecutor.ExecuteAsync(
+                syncMethod.GetMethodInfo(),
+                _controller,
+                new Dictionary<string, object>() { { "input", null } });
+
+            // Assert
+            Assert.Null(result);
+        }
+
         [Fact]
         public async Task AsyncAction_WithCustomTaskReturnTypeThrows()
         {

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

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using System.ComponentModel;
 using System.Threading.Tasks;
 
 namespace Microsoft.AspNet.Mvc.Core.Test
@@ -85,6 +86,16 @@ namespace Microsoft.AspNet.Mvc.Core.Test
             throw new NotImplementedException();
         }
 
+        public string EchoWithDefaultValue([DefaultValue("hello")] string input)
+        {
+            return input;
+        }
+
+        public string EchoWithDefaultValueAndAttribute([DefaultValue("hello")] string input = "world")
+        {
+            return input;
+        }
+
         public dynamic ReturnTaskAsDynamicValue(int i, string s)
         {
             return Task.Factory.StartNew(() => i);

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

@@ -0,0 +1,90 @@
+// 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;
+using System.Threading.Tasks;
+using Microsoft.AspNet.Builder;
+using Microsoft.Framework.DependencyInjection;
+using Xunit;
+
+namespace Microsoft.AspNet.Mvc.FunctionalTests
+{
+    public class DefaultValuesTest
+    {
+        private const string SiteName = nameof(BasicWebSite);
+        private readonly Action<IApplicationBuilder> _app = new BasicWebSite.Startup().Configure;
+        private readonly Action<IServiceCollection> _configureServices = new BasicWebSite.Startup().ConfigureServices;
+
+        [Fact]
+        public async Task Controller_WithDefaultValueAttribut_ReturnsDefault()
+        {
+            // Arrange
+            var expected = "hello";
+
+            var server = TestHelper.CreateServer(_app, SiteName, _configureServices);
+            var client = server.CreateClient();
+
+            var url = "http://localhost/DefaultValues/EchoValue_DefaultValueAttribute";
+
+            // Act
+            var response = await client.GetStringAsync(url);
+
+            // Assert
+            Assert.Equal(expected, response);
+        }
+
+        [Fact]
+        public async Task Controller_WithDefaultValueAttribute_ReturnsModelBoundValues()
+        {
+            // Arrange
+            var expected = "cool";
+
+            var server = TestHelper.CreateServer(_app, SiteName, _configureServices);
+            var client = server.CreateClient();
+
+            var url = "http://localhost/DefaultValues/EchoValue_DefaultValueAttribute?input=cool";
+
+            // Act
+            var response = await client.GetStringAsync(url);
+
+            // Assert
+            Assert.Equal(expected, response);
+        }
+
+        [Fact]
+        public async Task Controller_WithDefaultParameterValue_ReturnsDefault()
+        {
+            // Arrange
+            var expected = "world";
+
+            var server = TestHelper.CreateServer(_app, SiteName, _configureServices);
+            var client = server.CreateClient();
+
+            var url = "http://localhost/DefaultValues/EchoValue_DefaultParameterValue";
+
+            // Act
+            var response = await client.GetStringAsync(url);
+
+            // Assert
+            Assert.Equal(expected, response);
+        }
+
+        [Fact]
+        public async Task Controller_WithDefaultParameterValue_ReturnsModelBoundValues()
+        {
+            // Arrange
+            var expected = "cool";
+
+            var server = TestHelper.CreateServer(_app, SiteName, _configureServices);
+            var client = server.CreateClient();
+
+            var url = "http://localhost/DefaultValues/EchoValue_DefaultParameterValue?input=cool";
+
+            // Act
+            var response = await client.GetStringAsync(url);
+
+            // Assert
+            Assert.Equal(expected, response);
+        }
+    }
+}

test/WebSites/BasicWebSite/Controllers/DefaultValuesController.cs

@@ -0,0 +1,23 @@
+// 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.ComponentModel;
+using Microsoft.AspNet.Mvc;
+
+namespace BasicWebSite.Controllers
+{
+    public class DefaultValuesController : Controller
+    {
+        [HttpGet]
+        public string EchoValue_DefaultValueAttribute([DefaultValue("hello")] string input)
+        {
+            return input;
+        }
+
+        [HttpGet]
+        public string EchoValue_DefaultParameterValue(string input = "world")
+        {
+            return input;
+        }
+    }
+}