One of the core design principles of the ASP.NET MVC Framework is enabling great testing support.  Like the rest of the MVC framework, you can easily unit test routes and route matching rules.  The MVC Routing system can be instantiated and run independent of ASP.NET - which means you can load and unit test route patterns within any unit test library (no need to start up a web-server) and using any unit test framework (NUnit, MBUnit, MSTest, etc).

Although you can unit test an ASP.NET MVC Application's global RouteTable mapping collection directly within your unit tests, in general it is usually a bad idea to have unit tests ever change or rely on global state.  A better pattern that you can use is to structure your route registration logic into a RegisterRoutes() helper method like below that works against a RouteCollection that is passed in as an argument (note: we will probably make this the default VS template pattern with the next preview update):

Figure 25

You can then write unit tests that create their own RouteCollection instance and call the Application's RegisterRoutes() helper to register the application's route rules within it.  You can then simulate requests to the application and verify that the correct controller and actions are registered for them - without having to worry about any side-effects:

Figure 26