Moq, TDD and multiple layers - asp.net-mvc-3

Question

I have a data assembly which defines my repositories.
I then have a service assembly which defines my services, each service has a repository injected into the constructor by Ninject.
When I'm unit testing my service methods, everything is fine:
[TestClass]
public class UserTests
{
IQueryable<User> users;
int userID;
public UserTests()
{
users = new List<User>()
{
new User { EmailAddress = "known#user.com", Password = "password", ID = 1}
}.AsQueryable();
}
[TestMethod]
public void Known_User_Can_Login()
{
// Arrange
var repository = new Mock<IUserRepository>();
var service = new UserService(repository.Object);
repository.Setup(r => r.GetAll())
.Returns(users);
// Act
bool loggedIn = service.UserLogin("known#user.com", "password", out userID);
// Assert
Assert.IsTrue(loggedIn);
Assert.AreEqual(1, userID);
}
[TestMethod]
public void Unknown_User_Cannot_Login()
{
// Arrange
var repository = new Mock<IUserRepository>();
var service = new UserService(repository.Object);
repository.Setup(r => r.GetAll())
.Returns(users);
// Act
bool loggedIn = service.UserLogin("unknown#user.com", "password", out userID);
//
Assert.IsFalse(loggedIn);
}
}
However, I'm running into problems when testing my controller (another level down).
My controller has dependencies on a service, and the service depends on a repository. I can't seem to get my controller tests to work. Here's what I have so far:
[TestClass]
public class AccountTests
{
IQueryable<User> users;
public AccountTests()
{
users = new List<User>()
{
new User { CompanyId = 1, EmailAddress = "known#user.com", Password = "password"},
new User { CompanyId = 1, EmailAddress = "unknown#user.com", Password = "password"}
}.AsQueryable();
}
[TestMethod]
public void Known_User_Can_Login()
{
int userID = 0;
var repo = new Mock<IUserRepository>();
// Arrange
var service = new Mock<UserService>(repo.Object);
var controller = new AccountController(service.Object);
// Act
var result = controller.Login(new LoginModel { EmailAddress = "known#user.com", Password = "password" }) as RedirectToRouteResult;
// Assert
service.Verify(x => x.UserLogin("known#user.com", "password", out userID), Times.Once());
Assert.AreEqual("Index", result.RouteValues["Action"]);
}
}
I keep getting an error about instantiating the UserService (i'm attempting to pass an instance of the UserRepository to it but it isn't working).
I must be doing something daft, but what?

Answer 1

Make sure that UserService is an interface.
Also, you must not create an instance of IUserRepository in your second test as you are doing here:
var repo = new Mock<IUserRepository>();
// Arrange
var service = new Mock<UserService>(repo.Object);
Since UserService is mocked, it will not make calls to IUserRepository anyway and you don't have to supply it's dependencies when creating the mock.
What you need to do is simply create the mock for UserService this way:
var service = new Mock<UserService>();
Even tough UserService normally has a dependency on a repository, Moq will just supply canned responses to methods and thus won't need to make the calls to the an actual repository.

Answer 2

UserService class I am guessing is not an interface or an abstract class, if not then it is bound to fail since Mock cannot create an implementation of the UserService. Thus either create an interface for UserService or define it as an abstract class or instantiate it as follows:
var service = new UserService(repo.Object);
or you could use Mock.Create<UserService>() but you need to have provided all the implemenation UserService needs using Mock.Provide<T>() api.
Hope this helps.
If this isnt the problem please update the question with the classes for UserService and your repository