Question

I am in the process of writing some unit tests for my controllers in RC1. Here is the controller’s public signature I’m testing:

        [AcceptVerbs(HttpVerbs.Post)]     public ActionResult AcceptColleague()     { 

The implementation inside the AcceptColleague uses the TryUpdateModel(colleague) method of populating the Colleague object from the form fields. However, I’m running into a ‘Object reference not set to an instance of an object’ error on the TryUpdateModel line while trying to unit test the method.

Here is my unit test code:

            // definition         HomeController controller = new HomeController();         IColleagueRepository fakeColleagueRepo = MockRepository.GenerateMock<IColleagueRepository>();         Colleague requestedColleauge = new Colleague();         EmployeeInfo currentUser = new EmployeeInfo();                     HttpContextBase fakeHttpContext = MockRepository.GenerateMock<HttpContextBase>();         HttpRequestBase fakeHttpRequest = MockRepository.GenerateMock<HttpRequestBase>();         ControllerContext fakeContext = MockRepository.GenerateMock<ControllerContext>(fakeHttpContext, new RouteData(), controller);         NameValueCollection fakeForm = new NameValueCollection();          // expectations         fakeColleagueRepo.Expect(c => c.Read(1234)).Return(requestedColleauge);         fakeColleagueRepo.Expect(c => c.Update(requestedColleauge));         fakeColleagueRepo.Expect(c => c.Add(new Colleague())).IgnoreArguments().Constraints(Is.NotNull());         fakeContext.Expect(cx => cx.HttpContext).Return(fakeHttpContext);         fakeHttpContext.Expect(hcx => hcx.Request).Return(fakeHttpRequest);         fakeHttpRequest.Expect(hr => hr.Form).Return(fakeForm);          // setup         controller.ColleagueRepository = fakeColleagueRepo;         controller.ControllerContext = fakeContext;         requestedColleauge.TargetEmployeeInfoId = 123456;         requestedColleauge.GeneratedEmployeeInfoId = 654321;         currentUser.EmployeeInfoId = 123456;         fakeForm.Add('ColleagueId', '22222');          // action         RedirectToRouteResult result = controller.AcceptColleague() as RedirectToRouteResult;          // validation         Assert.IsNotNull(result, 'AcceptColleague() did not return RedirectToRouteResult'); 

Am I missing something on the mocking or should I be using a different public signature like AcceptColleague(Colleague colleague) and then testing the ModelState.IsValid property?

If so, how don’t see a way I can mock the read only ModelState property off of the controller?

Answer 1

TryUpdateModel and ModelState both require zero mocks in RC 1. The only thing that you have to supply is a ValueProvider. For that, you can use FormCollection.ToValueProvider().

You’ll still need to mock your repository, but there is nothing that you need to mock in the framework for this functionality. Try this:

    FormCollection fakeForm = new FormCollection();     fakeForm.Add('ColleagueId', '22222');     controller.ValueProvider = fakeForm.ToValueProvider();      // action 

Note: No mocked HttpContext needed, unless your code requires it.