public void Adding_Product_To_Cart_Goes_To_Cart_Screen() {
     // Arrange
     Mock<IProductRepository> mock = new Mock<IProductRepository>();
     mock.Setup(m => m.Products).Returns(new Product[] { new Product {ProductID = 1, Name = "P1", Category = "Apples"}, }.AsQueryable());
     
     // Arrange
     Cart cart = new Cart();
     
     // Arrange
     CartController target = new CartController(mock.Object);
     
     // Act
     RedirectToRouteResult result = target.AddToCart(cart, 2, "myUrl");
     
     // Assert
     Assert.AreEqual(result.RouteValues["action"], "Index");
     Assert.AreEqual(result.RouteValues["returnUrl"], "myUrl");
 }
        public void Can_Add_To_Cart() {
            
            // Arrange
            Mock<IProductRepository> mock = new Mock<IProductRepository>();

            mock.Setup(m => m.Products).Returns(new Product[] { new Product {ProductID = 1, Name = "P1", Category = "Apples"}, }.AsQueryable());

            // Arrange
            Cart cart = new Cart();

            // Arrange
            CartController target = new CartController(mock.Object);

            // Act
            target.AddToCart(cart, 1, null);

            // Assert
            Assert.AreEqual(cart.Lines.Count(), 1);

            Assert.AreEqual(cart.Lines.ToArray()[0].Product.ProductID, 1);

        }