如何对嵌套的 HTTP 调用进行单元测试答案

【问题标题】：How to unit test nested HTTP Calls如何对嵌套的 HTTP 调用进行单元测试
【发布时间】：2020-10-10 16:37:48
【问题描述】：

我正在尝试对以下功能进行单元测试：

async fetchGreatHouseByName(name: string) {
  const [house] = await this.httpGetHouseByName(name);
  const currentLord = house.currentLord ? house.currentLord : '957';
  const result: any = await this.httpGetLord(currentLord);
  const character = Characters.default.find(char => char.characterName === result.name);
  return {...house, character};
}

这个函数内部是多个 HTTP GET 调用。我知道如何测试它们，但我如何处理嵌套的 HTTP 调用，每个调用都是一个 Promise。

我得到了什么：

it('should get house from http', done => {
  const httpMock: HttpTestingController = TestBed.inject(HttpTestingController);

  const mockResponse = {
    name: 'House One',
    currentLord: 'Some Lord'
  };

  service.fetchGreatHouseByName('House One').then((house: House) => {
    expect(house).toBeTruthy();
    console.log(house);
  });

  const mockRequest = httpMock.expectOne(
    'https://www.anapioficeandfire.com/api/houses?name=House%20Lannister%20of%20Casterly%20Rock'
  );

  mockRequest.flush(mockResponse);

});

所以httpGetHouseByName 通常会返回类似mockRequest 的内容。还有httpGetLord 和包含name 的对象以及其他属性。这个 HTTP 调用是否还需要一个 mock，如果需要，我该如何使用它？

【问题讨论】：

标签： javascript angular typescript unit-testing jasmine

【解决方案1】：

我认为调用该函数应该将两个 HTTP 调用放入队列中。尝试依次刷新两个调用并将您的断言放入 .then 块中。

it('should get house from http', done => {
  const httpMock: HttpTestingController = TestBed.inject(HttpTestingController);

  const mockResponse = {
    name: 'House One',
    currentLord: 'Some Lord'
  };

  service.fetchGreatHouseByName('House One').then((house: House) => {
    expect(house).toBeTruthy();
    console.log(house);
    // your other assertions here
  });

  const mockRequest = httpMock.expectOne(
    'https://www.anapioficeandfire.com/api/houses?name=House%20Lannister%20of%20Casterly%20Rock'
  );

  mockRequest.flush(mockResponse);

  const response = {
     // mock response of httpGetLord here
    };
  const request = httpMock.expectOne(/* url of httpGetLord*/);
  request.flush(response);
});

【讨论】：