Moq a fake cookie in Asp.Net MVC Controller - asp.net-mvc

Question

This is my Action for my Login Controller. I am able to mock the action using Moq.
But i get an error when it hits this.HttpContext.Response.Cookies.Set(new HttpCookie("AcceptedDoDNotice") { Expires = DateTime.Now.AddDays(-1) });
Error:Additional information: Object reference not set to an instance of an object.
How do i Mock the cookie so i wont get the error above?
public ActionResult Login(LoginViewModel model)
{
if (ModelState.IsValid)
{
var user = _uow.UserRepository.FindLogin(model.Email, model.Password);
if (user != null)
{
_uow.UserRepository.UpdateLastLoginDate(user);
_uow.SaveChanges();
this.HttpContext.Response.Cookies.Set(new HttpCookie("MyCookie") { Expires = DateTime.Now.AddDays(-1) });
if (user.UserLevel.IsAdmin)
return RedirectToAction("Index", "Administrator");
}
else
{
ModelState.AddModelError("", "Invalid username or password.");
}
}
return View(model);
}
The Moq test is below:
//Arrange
var model = new LoginViewModel();
model.Email = realEmail;
model.Password = realPassword;
//Act
var loginController = new LoginController();
var result = loginController.Login(model) as RedirectToRouteResult;
var actual = result.RouteValues["controller"].ToString();
//Assert
actual.Should().Be("Administrator");

Answer 1

You need to mock the controller context. This will allow you to provide a mocked response which in turn provides a cookie collection that you control. You can then see exactly which cookies were set on the response.
var cookieCollection = new HttpCookieCollection { };
var response = new Mock<HttpResponseBase>();
response.SetupGet(r => r.Cookies).Returns(cookieCollection);
var context = new Mock<HttpContextBase>();
context.SetupGet(x => x.Response).Returns(response.Object);
var loginController = new LoginController();
loginController.ControllerContext = new ControllerContext(context.Object, new RouteData(), loginController);
var model = new LoginModel { };
var result = loginController.Login(model) as RedirectToRouteResult;
var actual = result.RouteValues["controller"].ToString();
//Assert
actual.Should().Be("Administrator");
cookieCollection.Should().HaveCount(1);
// other assertions about your cookie