如何用TDD/BDD开发输入对象?

我有一个方法叫做 ProcessPayment()

Given a payment processing context,
When payment is processed with valid payment information,
Then it should return a successful gateway response code.

为了设置上下文,我正在使用Moq存根我的网关服务。

_mockGatewayService = Mock<IGatewayService>();
_mockGatewayService.Setup(x => x.Process(Moq.It.IsAny<PaymentInfo>()).Returns(100);

规格如下:

public class when_payment_is_processed_with_valid_information {

    static WebService _webService;
    static int _responseCode;
    static Mock<IGatewayService> _mockGatewayService;
    static PaymentProcessingRequest _paymentProcessingRequest;

    Establish a_payment_processing_context = () => {

        _mockGatewayService = Mock<IGatewayService>();
        _mockGatewayService
            .Setup(x => x.Process(Moq.It.IsAny<PaymentInfo>())
            .Returns(100);

        _webService = new WebService(_mockGatewayService.Object);

        _paymentProcessingRequest = new PaymentProcessingRequest();
    };

    Because payment_is_processed_with_valid_payment_information = () => 
        _responseCode = _webService.ProcessPayment(_paymentProcessingRequest); 

    It should_return_a_successful_gateway_response_code = () => 
        _responseCode.ShouldEqual(100);

    It should_hit_the_gateway_to_process_the_payment = () => 
        _mockGatewayService.Verify(x => x.Process(Moq.It.IsAny<PaymentInfo>());

}

该方法应采用“PaymentProcessingRequest”对象(而不是域对象),将该对象映射到域对象,并将域对象传递给网关服务上的存根方法。网关服务的响应就是方法返回的响应。但是,由于我对网关服务方法的存根方式,它不关心传入的内容。因此,我似乎无法测试该方法是否正确地将请求对象映射到域对象。

我什么时候还能坚持BDD?