如何在 Angular2 中使用 MockBackend

Question

我有这项服务需要测试：

import { Injectable } from '@angular/core';
import { Http } from '@angular/http';

@Injectable()
export class LoginService {

  private baseUrl: string = 'http://localhost:4000/';

  constructor (private http: Http) {}

  public getBaseUrl() {
    return this.baseUrl;
  }

  getLogin() {
    return this.http.get(this.baseUrl + 'api/auth/octopus')
      .map(res => res.json().redirect);
  }
}

要测试 getLogin() 函数，我有以下代码：

import {
  async,
  describe,
  it,
  expect,
  beforeEach,
  addProviders,
  inject
} from '@angular/core/testing';
import { provide} from '@angular/core';
import { LoginService } from './login.service';
import {
  Http,
  BaseRequestOptions,
} from '@angular/http';
import {MockBackend} from '@angular/http/testing';


describe('Service: LoginService', () => {

  beforeEach(() => addProviders([
    LoginService,
    BaseRequestOptions,
    MockBackend,
    provide(Http, {
      useFactory: (backend: MockBackend, defaultOptions: BaseRequestOptions) => {
        return new Http(backend, defaultOptions);
      },
      deps: [MockBackend, BaseRequestOptions]
    })
  ]));

  it('should return data.',
    async(inject([LoginService], (loginService: LoginService) => {
      loginService.getLogin().subscribe(
        data => console.log(data)
      );
    })
  ));

});

但是，数据不会被记录。 我尝试了在 SO 或 Internet 上找到的各种解决方案。

其中一个是对 mockbackend 进行 http 调用，但这只是给了我 data = undefined。

Answer 1

您需要注入 MockBackend 并订阅连接，如下所示：

更新

async(inject([LoginService, MockBackend], (loginService: LoginService, mockBackend:MockBackend) => {
  let mockResponse = new Response(new ResponseOptions({body: {'redirect': 'some string'}}))
  mockBackend.connections.subscribe(c => c.mockRespond(mockResponse));
  loginService.getLogin().subscribe(
    data => console.log(data)
  );
})

更多详情请看这里：

https://angular.io/docs/ts/latest/api/http/testing/index/MockBackend-class.html