public void AccountService_Register_CanNotRegister_Failure() { // Arrange IMember existedMember = Substitute.For <IMember>(); ErrorCodeType expectedError = ErrorCodeType.MemberAlreadyExists; UserToRegister user = GetUserToRegister(); _memberService.GetByEmail(user.Email).Returns(existedMember); // Act Result registrationResult = _accountService.Register(user); // Assert Assert.IsNotNull(registrationResult, Common.ShowResponseTypeMismatchMessage(typeof(Result))); Assert.IsTrue(registrationResult.IsFailure, Common.ShowNotSatisfiedExpectationMessage(true, "registrationResult.IsFailure")); Assert.AreEqual(expectedError, registrationResult.ErrorCode, Common.ShowNotSatisfiedExpectationMessage(expectedError, registrationResult.ErrorCode)); _userRegistration.ReceivedWithAnyArgs(0).Register(null); }