Testing ASP.NET MVC routes using NUnit and FakeItEasy

Let's say we have registered routes in our ASP.NET MVC application:

 routes.MapTrailingSlashRoute(  
   "Topic", // Route name  
   "news/{url}", // URL with parameters  
    new { controller = "Topic", action = "Index" } // Parameter defaults  
 );  
 
 routes.MapTrailingSlashRoute(  
   "Default", // Route name  
   "{controller}/{action}/{id}", // URL with parameters  
   new { controller = "Home", action = "Index" , id = "" } // Parameter defaults  
 );  

How can we test this routes using NUnit testing framework and FakeItEasy mocking framework?

Here's an example of how this can be done:

     [TestFixture]  
     [Category("Unit")]  
     public class when_using_registered_routes  
     {                    
       [TestFixtureSetUp]  
       public void Prepare()  
       {  
         MvcApplication.RegisterRoutes(RouteTable .Routes);   
       }  
       [Test]  
       [TestCase("~/", "Home", "Index" )]        
       [TestCase( "~/news/testing-routes-in-mvc/", "Topic" , "Index" )]  
       [TestCase("~/discussion/all/", "Discussion", "All")]        
       [TestCase( "~/discussion/widget/", "Discussion" , "Widget" )]  
       public void should_return_expected_controller_and_action(string path, string expectedController, string expectedAction)  
       {                  
         var httpContext = A.Fake<HttpContextBase>();          
         A.CallTo(() => httpContext.Request.AppRelativeCurrentExecutionFilePath).Returns(path);                  
         var routeData = RouteTable.Routes.GetRouteData(httpContext);  
         Assert.That(routeData.Values["controller"].ToString().ToLower(), Is.EqualTo(expectedController.ToLower()));  
         Assert.That(routeData.Values["action"].ToString().ToLower(), Is.EqualTo(expectedAction.ToLower()));  
       }       
     }