Angular 在异步函数内部比较数据时，HttpClient 单元测试不会失败

Question

我正在尝试对几个简单的 GET 请求进行单元测试，但无论我做什么，我都无法让测试失败。

如果我将 ('GET') 更改为 ('POST') 它将失败，但是所有 api 数据无论如何都会通过。

import { HttpClientTestingModule, HttpTestingController } from '@angular/common/http/testing';
import { TestBed } from '@angular/core/testing';

import { mockPhoneNumbers } from '../mocks/data/phoneNumbers.mock';
import { PhoneNumberApiService } from './phone-number-api.service';

describe('PhoneNumberApiService', () => {
  let service: PhoneNumberApiService;
  let httpTestingController: HttpTestingController;

  beforeEach(() => {
    TestBed.configureTestingModule({
      imports: [HttpClientTestingModule],
      providers: [PhoneNumberApiService],
    });

    service = TestBed.get(PhoneNumberApiService);
    httpTestingController = TestBed.get(HttpTestingController);
  });

  afterEach(() => {
    // After every test, assert that there are no more pending requests.
    httpTestingController.verify();
  });

  it('should be created', () => {
    expect(service).toBeTruthy();
  });

  it('should get the phone numbers successfully', () => {
    service
      .getPhoneNumbers()
      .subscribe(phoneNumbers => {
        expect(phoneNumbers).toEqual('bob');
        expect(phoneNumbers[0].id).toEqual('b8bfea4d-a26f-9e4e-cbd4-39eb69cdaa58');
        expect(phoneNumbers[1].friendlyName).toEqual('Dev Test');
      });

    const req = httpTestingController.expectOne('phoneNumbers');

    expect(req.request.method).toEqual('GET');

    req.flush(mockPhoneNumbers);
  });

  it('should get the phone number details successfully', () => {
    const { id: phoneNumberId } = mockPhoneNumbers[0];

    service
      .getPhoneNumberDetails(phoneNumberId)
      .subscribe(phoneNumber => expect(phoneNumber).toEqual(mockPhoneNumbers[0]));

    const req = httpTestingController.expectOne(`phoneNumbers/${phoneNumberId}`);

    expect(req.request.method).toEqual('GET');

    req.flush('bob');
  });
});

当然用模拟数据刷新请求然后期望模拟数据是 bob 是错误的。在底部测试中，使用 bob 刷新请求并期望数据等于数组中的第一个 phone 数字应该会失败。

Answer 1

关于你的测试的问题是你让你的 "it" 函数和预期异步没有明确告诉茉莉花.

您需要在其他地方使用 done 函数来告诉测试正在等待什么（查看 here 关于 jasmine 异步测试的好教程）

下面是一个基于您的代码的示例：

...
//Receive the done function like this
it('should get the phone numbers successfully', (done) => {
    service
      .getPhoneNumbers()
      .subscribe(phoneNumbers => {
        expect(phoneNumbers).toEqual('bob');
        expect(phoneNumbers[0].id).toEqual('b8bfea4d-a26f-9e4e-cbd4-39eb69cdaa58');
        expect(phoneNumbers[1].friendlyName).toEqual('Dev Test');
        //Tell the test that only in here all the work was done
        done();
      });
    const req = httpTestingController.expectOne('phoneNumbers');

    expect(req.request.method).toEqual('GET');

    req.flush(mockPhoneNumbers);
});
....

此外，为了回答，jest 是一个测试运行器，构建在 jasmine 框架之上（这意味着 jest 语法类似于 jasmin，但不相同）。但是对于这种情况，我想使用 done 可以解决你的问题。

Angular 在异步函数内部比较数据时，HttpClient 单元测试不会失败

Angular HttpClient unit tests won't fail when comparing data inside of an asynchronous function

unit-testing

angular

angular-httpclient