Adding a functional test that modifies data tokens

Tracked by aspnet/Routing#116

The product support for this feature is in already this change just adds a
test verifying the scenario.

test/Microsoft.AspNet.Mvc.FunctionalTests/RouteDataTest.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.Collections.Generic;
 using System.Net;
 using System.Threading.Tasks;
 using Microsoft.AspNet.Builder;
@@ -70,9 +71,42 @@ namespace Microsoft.AspNet.Mvc.FunctionalTests
                 result.Routers);
         }
 
+        // Verifies that components in the MVC pipeline can modify datatokens
+        // without impacting any static data.
+        //
+        // This does two request, to verify that the data in the route is not modified
+        [Fact]
+        public async Task RouteData_DataTokens_FilterCanSetDataTokens()
+        {
+            // Arrange
+            var server = TestServer.Create(_services, _app);
+            var client = server.CreateClient();
+
+            var response = await client.GetAsync("http://localhost/Routing/DataTokens");
+
+            // Guard
+            var body = await response.Content.ReadAsStringAsync();
+            var result = JsonConvert.DeserializeObject<ResultData>(body);
+            Assert.Single(result.DataTokens);
+            Assert.Single(result.DataTokens, kvp => kvp.Key == "actionName" && ((string)kvp.Value) == "DataTokens");
+
+            // Act
+            response = await client.GetAsync("http://localhost/Routing/Conventional");
+
+            // Assert
+            Assert.Equal(HttpStatusCode.OK, response.StatusCode);
+
+            body = await response.Content.ReadAsStringAsync();
+            result = JsonConvert.DeserializeObject<ResultData>(body);
+
+            Assert.Single(result.DataTokens);
+            Assert.Single(result.DataTokens, kvp => kvp.Key == "actionName" && ((string)kvp.Value) == "Conventional");
+        }
 
         private class ResultData
         {
+            public Dictionary<string, object> DataTokens { get; set; }
+
             public string[] Routers { get; set; }
         }
     }

test/WebSites/BasicWebSite/Controllers/RoutingController.cs

@@ -19,10 +19,29 @@ namespace BasicWebSite
             return GetData();
         }
 
+        public object DataTokens()
+        {
+            return GetData();
+        }
+
+        public override void OnActionExecuting(ActionExecutingContext context)
+        {
+            if (!context.RouteData.DataTokens.ContainsKey("actionName"))
+            {
+                context.RouteData.DataTokens.Add("actionName", context.ActionDescriptor.Name);
+            }
+        }
+
         private object GetData()
         {
             var routers = ActionContext.RouteData.Routers.Select(r => r.GetType().FullName).ToArray();
-            return new { Routers = routers };
+            var dataTokens = ActionContext.RouteData.DataTokens;
+
+            return new
+            {
+                DataTokens = dataTokens,
+                Routers = routers
+            };
         }
     }
 }