Unit testing a controller action method using MOQ

I have the following controller action method.

[HttpPost]
    public ActionResult CreateProvider(Provider provider)
    {
        try
        {
            int providerCreationSuccessful = _repository.CreateProvider(provider);
            if (providerCreationSuccessful == 2)
                TempData["userIntimation"] = "Provider Registered Successfully";

            //return RedirectToAction("ShowTheListOfProviders");
        }
        catch (Exception Ex)
        {
            _logger.Error(Ex.Message);
            return View("Error");
        }
        return Json(new { url = Url.Action("ShowTheListOfProviders", "Provider") });
    }

I had written the following Test case for the above method,which was working

[TestMethod()]
    public void CreateProviderTest()
    {
        mockProviderRepository.Setup(provider => provider.CreateProvider(_provider)).Returns(new int());
        var providerCreationResult = _providerController.CreateProvider(_provider) as ActionResult;
        Assert.IsNotNull(providerCreationResult);
    }

As can be seen from my code in the action method,I am redirecting using AJAX,hence returning JSON of the url to be redirected to.

Now,the test is obviously failing.I am new to unit tests and was wondering,what updates I needed to make to the Testmethod for it to pass.Please guide me.Thanks.