Angular 4.3中的单元测试HttpClientModule：来自HttpTestingController.expectOne(url)的未定义返回值

我试图了解如何使用作为新httpClientModule的一部分提供的模拟功能.我的测试代码几乎完全匹配现有文档中显示的内容.但是,doc示例并不完整 – 例如,至少缺少TESTBad和inject的import语句.我假设来自@ angular / common / http的httpClient也是如此.我的测试代码添加了这些.

此测试失败,因为在httpmock.expectOne调用之后req最终未定义.我很欣赏为什么会这样.

import { TESTBed,inject } from '@angular/core/tesTing';
import { httpClient } from '@angular/common/http';
import { httpClientTesTingModule,httpTesTingController } from '@angular/common/http/tesTing';

describe('httpClientTesTingModule',() => {
  beforeEach(() => TESTBed.configureTesTingModule({
    imports: [ httpClientTesTingModule ],providers: [ httpClient,httpTesTingController]
  }));

  it('expects a GET request',inject([httpClient,httpTesTingController],(http: httpClient,httpmock: httpTesTingController) => {
    http
      .get('/data')
      .subscribe(data => expect(data['name']).toEqual('Test Data'));

    const req = httpmock.expectOne('/data');
    expect(req).toBeDefined();
    expect(req.request.method).toEqual('GET');
    req.flush({name: 'Test Data'});
    httpmock.verify();
  }));
});