Unit testing a class that inherits from an abstract class

Question

My problem is that I want to stub a property in my abstract class, because my class in test uses that property. I'm currently using latest version of Moq.

My abstract class looks like this:

public abstract class BaseService
{
    protected IDrawingSystemUow Uow { get; set; }
}

And my class in test looks like this:

public class UserService : BaseService, IUserService
{
    public bool UserExists(Model model)
    {
        var user = this.Uow.Users.Find(model.Id);
        if(user == null) { return false; }

        reurn true;
    }
}

I can't figure out how I can stub the Uow property. Does anybody have any clue? Or is my design that bad that I need to move to Uow property to my class in test?

Answer 1

Your current setup won't work for one simple reason - Uow property is non-overridable and Moq's job is done at this point. Cannot override, cannot mock.

Easiest solution is to simply make that property overridable. Change your base class definition to:

public abstract class BaseService
{
    protected virtual IDrawingSystemUow Uow { get; set; }
}

Now you can use Moq's protected feature (this requires you to include using Moq.Protected namespace in your test class):

// at the top of the file
using Moq.Protected;

// ...

var drawingSystemStub = new Mock<IDrawingSystemUow>();
var testedClass = new Mock<UserService>();
testedClass 
  .Protected()
  .Setup<IDrawingSystemUow>("Uow")
  .Returns(drawingSystemStub.Object);

// setup drawingSystemStub as any other stub

// exercise test
var result = testedClass.Object.UserExists(...);