Unit Testing MVC Authentication VS 2013

Question

I'm trying to learn about Unit Testing with the new VS2013 Default MVC w/ Authentication Project. One of the first things I want to test is registering a user. (I know I probably don't need to unit test this since it's already MS tested code but I want to use this to understand the basics). I've also heard that the new Membership code is more 'testable' so I don't need to create my own membership interfaces, etc...

I'm using NSubstitute as a faking framework.

Looking at the Account Controller -> Register() async method

namespace WebApplication1.Controllers
{
    [Authorize]
    public class AccountController : Controller
    {
        public AccountController()
        : this(new UserManager<ApplicationUser>(new UserStore<ApplicationUser>(new ApplicationDbContext())))
        {
        }

        public AccountController(UserManager<ApplicationUser> userManager)
        {
            UserManager = userManager;
        }

        public UserManager<ApplicationUser> UserManager { get; private set; }

        ...


       //
       // POST: /Account/Register
       [HttpPost]
       [AllowAnonymous]
       [ValidateAntiForgeryToken]
       public async Task<ActionResult> Register(RegisterViewModel model)
       {
           if (ModelState.IsValid)
           {
                var user = new ApplicationUser() { UserName = model.UserName };
                var result = await UserManager.CreateAsync(user, model.Password);
                if (result.Succeeded)
                {
                    await SignInAsync(user, isPersistent: false);
                    return RedirectToAction("Index", "Home");
                }
                else
                {
                   AddErrors(result);
                }
           }

           // If we got this far, something failed, redisplay form
           return View(model);
       }

If I wanted to write a simple test (ex. Register_RegisterValidUser), how would I do this? I know I need to substitute for the UserManager somehow but this did not work for me:

var substitute = Substitute.For<UserManager<ApplicationUser>>();

I also understand that I need to bypass the async Task<> functions using Task.FromResult but I'm not sure how to return a valid objects from the CreateAsync() and the SigninAsync() methods.

Can somebody help with some sample test code? Many thanks!

Answer 1

To mock the user manager with NSubstitute you have to use this:

var userStore = Substitute.For<IUserStore<ApplicationUser>>();
var userManager = Substitute.For<UserManager<ApplicationUser>>(userStore);

Now you can fake the methods result too. For example:

userManager.FindByNameAsync(Arg.Any<string>()).Returns(Task.FromResult(new ApplicationUser()));

Hope this help you.