Testing Specific Method Calls with Parameters using Moq

Question

I'm trying to write a Unit Test with Moq to verify that a Registration was successful. My Test is as follows:

    [TestMethod()]
    public void RegisterTest()
    {
        //Arrange
        var MockRepo = new Mock<IDataRepo>() ;             
        RegisterModel model = new RegisterModel
        {
            ConfirmPassword = "SamePassword",
            Email = "[email protected]",
            FirstName = "MyFirstName",
            LastName = "MyLastName",
            MiddleName = "MyMiddleName",
            Password = "SamePassword"
        };
        MockRepo.Setup(ctx => ctx.Add(model)).Verifiable("Nothing was added to the Database");

        //Act
        AccountController target = new AccountController(MockRepo.Object);

        //Assert
        ActionResult actual = target.Register(model);
        MockRepo.Verify(ctx => ctx.Add(It.IsAny<RegisterModel>()));
        Assert.IsInstanceOfType(actual, typeof(ViewResult));
    }

But it fails with the following Error

 Expected invocation on the mock at least once, but was never performed: ctx => ctx.Add(It.IsAny()) 

However, When I debugged the Test Method, I noticed that the Add(T) method was actually called. The MOQ dll version is v4.0

UPDATE Account Controller:

public class AccountController : Controller
{

    private IDataRepo _repo;

    public AccountController(IDataRepo Repo)
    {
        _repo = Repo;
    }

    public ActionResult Register(RegisterModel model)
    {
        if (ModelState.IsValid)
        {
            User user = _repo.Users.Where(u => u.Email == model.Email).FirstOrDefault();
            if (user == null)
            {
                _repo.Add(new User
                {
                    Email = model.Email,
                    Password = model.Password,
                    FirstName = model.FirstName,
                    LastName = model.LastName,
                    MiddleName = model.MiddleName
                });

                return View("RegistrationSuccess");
            }
            else
            {
                ModelState.AddModelError("UserExists", "This Email already Exists");
            }
        }
        return View(model);
    }
}

Answer 1

Your problem is that your Mock expects a RegisterModel instance

RegisterModel model = new RegisterModel
{
    ConfirmPassword = "SamePassword",
    Email = "[email protected]",
    FirstName = "MyFirstName",
    LastName = "MyLastName",
    MiddleName = "MyMiddleName",
    Password = "SamePassword"
};

MockRepo.Setup(ctx => ctx.Add(model))

but the Add method gets called with an instance of the User class

_repo.Add(new User
{
    Email = model.Email,
    Password = model.Password,
    FirstName = model.FirstName,
    LastName = model.LastName,
    MiddleName = model.MiddleName
});

---

So, one way to get around this is to setup the mock to accept a User instance.

RegisterModel model = new RegisterModel
{
    ConfirmPassword = "SamePassword",
    Email = "[email protected]",
    FirstName = "MyFirstName",
    LastName = "MyLastName",
    MiddleName = "MyMiddleName",
    Password = "SamePassword"
};
User expected = new User
{
    Email = model.Email,
    Password = model.Password,
    FirstName = model.FirstName,
    LastName = model.LastName,
    MiddleName = model.MiddleName
};
MockRepo.Setup(ctx => ctx.Add(expected))

Answer 2

I discovered an easier way to do it. Rather than generate your own User object you could call It.IsAny<User>() and the test would run just fine. so my unit test now becomes..

        //Arrange
        var MockRepo = new Mock<IDataRepo>() ;             
        var MockMembership = new Mock<IMembership>();
        RegisterModel model = new RegisterModel
        {
            ConfirmPassword = "SamePassword",
            Email = "[email protected]",
            FirstName = "MyFirstName",
            LastName = "MyLastName",
            MiddleName = "MyMiddleName",
            Password = "SamePassword"
        };

        MockRepo.Setup(ctx => ctx.Add(It.IsAny<User>())).Verifiable("Nothing was added to the Database");
        //Act
        AccountController target = new AccountController(MockRepo.Object, MockMembership.Object);

        //Assert
        ActionResult actual = target.Register(model);
        MockRepo.Verify(ctx => ctx.Add(It.IsAny<User>()));
        Assert.IsInstanceOfType(actual, typeof(ViewResult));