如何使用嵌套操作/回调对方法进行单元测试

How to unit test a method with a nested action / callback

我想测试一个发送 Web 请求并接收响应的方法。 然而,这不会直接发生,而是使用另一个 class 来构建请求并发送它。此外,HttpRequest class 对从 "building class" 传递的响应使用回调,它是从我要测试的方法中获取的。

一些代码会使它更清楚。 (简体)

// this is the actual method I want to unit test
public void GetSomeDataFromTheWeb(Action<ResponseData> action, string data)
{
    _webService.GetSomeDataFromTheWeb((req, resp) =>
    {
        // building the response depending on the HttpStatus etc
        action(new ResponseData());
    },data);
}

// this is the "builder method" from the _webService which I am gonna mock in my test
  public void GetSomeDataFromTheWeb(Action<HTTPRequest, HTTPResponse> response, string data)
{
    HTTPRequest request = new HTTPRequest(new Uri(someUrl)), HTTPMethods.Get,
        (req, resp) =>
        {
            response(req, resp);
        });            
    request.Send();
}

我可以创建一个 HttpResponse 它应该看起来的样子,但我不知道如何得到这个 "into" 最后一个方法的 response(req,resp) 调用。

我如何模拟 _webService 它从我要测试的方法中调用正确的回调 HttpResponse 我将输入我的单元测试?

基本上是这样的:

[Fact]
public void WebRequestTest()
{
  var httpresponse = ResponseContainer.GetWebRequestResponse();
  var webserviceMock = new Mock<IWebService>();

  //get the response somehow into the mock
  webserviceMock.Setup(w=>w.GetSomeDataFromTheWeb( /*no idea how*/));

  var sut = new MyClassIWantToTest(webserviceMock);

  ResponseData theResult = new ResponseData();
  sut.GetSomeDataFromTheWeb(r=>{theResult = r}, "");

  Assert.Equal(theResult, ResultContainer.WebRequest());
}

使用 It.IsAny 参数设置 GetSomeDataFromTheWeb 并使用设置中的 Callback 获取操作并使用存根调用它。

https://github.com/Moq/moq4/wiki/Quickstart#callbacks

webserviceMock
    .Setup(w=>w.GetSomeDataFromTheWeb( It.IsAny<Action<HTTPRequest, HTTPResponse>>, It.IsAny<string>))
    .Callback((Action<HTTPRequest, HTTPResponse> response, string data)=>{...});