Question

I’m beginner at Unit Testing. Please help me

I have class UserData UserData.cs

public partial class UserData
{

    /// <summary>
    /// return all not locked users
    /// </summary>
    /// <returns></returns>
    public static List<UserData> GetAllNotLockedUsers()
    {
        using (var db = new VostokPortalEntities())
        {
            var result = db.UserData.Where(i => !i.IsLocked).ToList();
            return result;
        }
        throw new Exception("cannot get users");
    }
}

I have controller action

    [HttpGet]
    public ActionResult Index()
    {           
        //get all user list
        var users = UserData.GetAllNotLockedUsers();
        return View(users);
    }

I have method for testing

[TestMethod]
public void UserPageUnAuth()
{
    var fakedHttpContext = TestCore.FakeHttpContext();
    var homeController = new HomeController(fakedHttpContext);
    var indexResult = homeController.Index() as ViewResult;
    Assert.IsNotNull(indexResult);
}

I’d like to test this using Mock.
What should I do?
Should I rewrite class with repository pattern? Is this neccessary?
Should I rewrite controller logic?
Should I add some code to EF auto-generated classes
Are there articles in Internet about unit testing for beginners?
Is there simple way to do mocking of EF?

Answer 1

Moving DB operations to a Repository class is a good idea. You should start with creating an interface for the repository.

public interface IUserRepository
{
    IEnumerable<User> GetAllNotLockedUsers();
}

Then you should implement a non-static repository class.

public class UserRepository : IUserRepository
{
    public IEnumerable<User> GetAllNotLockedUsers()
    {
        using (var db = new VostokPortalEntities())
        {
            var result = db.UserData.Where(i => !i.IsLocked).ToList();
            return result;
        }
    }
}

Since repository is not static anymore you have to instantiate it somewhere before using it. However the code below will not be testable.

[HttpGet]
public ActionResult Index()
{           
    var repository = new UserRepository();
    return View(repository.GetAllNotLockedUsers());
}

Repository is created inside the function so you can’t replace it with a mock for testing. You can inject this object using constructor injection.

public class MyController : Controller
{
    private readonly IUserRepository _repository;

    public MyController(IUserRepository repository)
    {
        _repository = repository;
    }
}

Now MyController is testable because you can inject a mock instance instead of the concrete implementation.

[Test]
public void RepositoryTest()
{
    //using Moq here
    Mock<IUserRepository> repositoryMock = new Mock<IUserRepository>();
    MyController controller = new MyController(repositoryMock.Object);
}

However default controller factory will not be able to create a controller without a parameterless constructor. It doesn’t know anything about your repository implementation. From this point on, you should get the help of a DI container for creating your controllers. I will not go in detail about that, you can take a look at this blog post