MVC Unit Testing Asserts with Rhino Mocks

When I first started learning to use mocking frameworks I was lucky enough to start on Moq which was nice and simple. Whenever I needed to know something there was one single google code page which told everything. Nice! Rhino Mock by example I find hard work, so I put this cheat sheet together to help get up and running quickly.

Rhino Mock Asserts

public void RhinoMockExampleAsserts()
{               
    // Example assert _principal.IsInRole(..) wasn't called
    _principal.AssertWasNotCalled(x => x.IsInRole(Arg<string>.Is.Anything))
    
    // Assert API call was made
    _apiClient.AssertWasCalled(x => x.GetCustomerStatement(Arg<int>.Is.Anything));
    
    // Assert API call was made with a specific ID
    _apiClient.AssertWasCalled(x => x.GetCustomerStatement(Arg<int>.Is.Equal(200));
    
    // Was called 3 times
    _principal.AssertWasCalled(x => x.IsInRole(Arg<string>.Is.Anything), x => x.Repeat.Times(3));

    // Was called once
    _principal.AssertWasCalled(x => x.IsInRole(Arg<string>.Is.Equal(usersGroup)), x => x.Repeat.Once());
    
    // Accessing parameters from a called method using Rhino Mock
    // _sessionTokenWriter.WriteSessionTokenToCookie(ClaimsPrincipal cp)
    var mockArgs = _mockSessionTokenWriter
                    .GetArgumentsForCallsMadeOn(
                        x => x.WriteSessionTokenToCookie(Arg<ClaimsPrincipal>.Is.Anything),
                        x => x.IgnoreArguments());  // setupConstraints(?) is of type Action<IMethodOptions<object>>

    // mockArgs is IList<object[]> a list of arrays. 
    // Where mock[i][n] where i is number of calls? And n is the nth parameter in that call?
    var claims = (mockArgs[0][0] as ClaimsPrincipal).Claims;
}

MVC Asserts

public void ExampleMvcAsserts()
{                      
    // Setup an error in the model so that ModelState.IsValid returns false.
    // Used to check that the ModelState.IsValid check is in place.
    controller.ViewData.ModelState.AddModelError("Surname", "The Surname field is required.");
   
    // Call the controller method. This usually returns an ActionResult, which may need to be cast.
    var result = _userController.Create(user).Result;
   
    // Assert that the redirect result is of a particular type
    Assert.That(result, Is.TypeOf<RedirectToRouteResult>());           
   
    // Assert that the controller redirects to the correct view
    Assert.AreEqual("Index", ((RedirectToRouteResult)result).RouteValues["action"]);
   
    // Check manaully added model state errors
    Assert.IsTrue(controller.ModelState.Keys.Contains("Email"));
    Assert.AreEqual("The Email address is already in use.", controller.ModelState["Email"].Errors[0].ErrorMessage);
                           
    // Check the model class is returned correctly in the view.
    var userModel = viewResult.Model as User;
    Assert.AreEqual(userModel.Forename, "John");
}

Aysnc Considerations

public void AsyncExamples()
{
    // Async controller actions have to be called asyn:
    await controller.Create(model);
   
    // Async methods return a task, so use Task.FromResult:
    _apiClient.Stub(x => x.GetCustomersAsync(Arg<long>.Is.Anything))
                .Return(Task.FromResult(new List<Customer>()));
                                       
    // If the method returns just Task and not Task<T> use true/null/1:
    _file.Stub(x => x.SavePostedFile(Arg<HttpPostedFileBase>.Is.Anything))
                .Return(Task.FromResult(true));
}