public void AmountBetween20and500_UseExpensivePaymentGateway() { cheapPaymentGateway.Stub(r => r.DoPayment()).Return(false); expensivePaymentGateway.Stub(r => r.DoPayment()).Return(true); CreditCard card = new CreditCard(); card.Amount = 300; card.CreditCardNo = "2421453325661532"; card.CardHolder = "Aakriti"; card.ExpirationDate = DateTime.MaxValue; card.SecurityCode = "242"; var response = controller.ProcessPayment(card); Assert.AreEqual(response.StatusCode, HttpStatusCode.OK); }