刷新一系列 Angular HTTP TestRequest

Question

我有一个 async 函数需要发出 POST 请求，但有些数据必须先从服务器获取：

async createObject() {
  // HTTP request #1: dep1 is needed for the second request
  const dep1 = await this.http.get("/urlA")
    .pipe(first())
    .toPromise();
  // Create the request object out of dep1 and some additional values
  const req = mkCreateParams(this.name, dep1);
  // HTTP request #2: Build something
  const res = await this.http.post("/urlB")
    .pipe(first())
    .toPromise();
  // When everything is done: Navigate away
  this.router.navigateByUrl(`/urlC/${res.id}`);

  return res;
}

我使用以下代码对此进行测试：

const httpTesting = TestBed.inject(HttpTestingController);
const req = testInstance.createObject();

httpTesting
  .expectOne("/urlA")
  .flush({ /* ... SNIP ... */);

const generatedId = "f9f64792-0ceb-4e3c-ae7b-4c7a8af6a552";
httpTesting
  .expectOne({ method: "POST", url: "/urlB" })
  .flush({ id: generatedId });

const res = await req;
expect(res.id).toEqual(generatedId);

这在期望 /urlB 时立即失败，甚至没有到达解析 res 的行。报错信息如下：

Expected one matching request for criteria "Match method: POST, URL: /urlB", found none.

这似乎是因为在调用 HttpTestingController.expectOne() 时必须已经发出请求。由于在 JavaScript 中急切地解决了 promises，所以第一个请求已经发出，但第二个请求还没有。

有没有办法告诉 Angular HttpTestingController 稍微放松一下，等待请求稍后到来？ HttpTestingController.verify 的存在暗示了这一点，但我不知道如何进入有用的状态。

Answer 1

我觉得等待承诺对你有帮助，试试fixture.whenStable()。

it('your title here', async done => {
  const httpTesting = TestBed.inject(HttpTestingController);
  const req = testInstance.createObject();

  httpTesting
    .expectOne("/urlA")
    .flush({ /* ... SNIP ... */);
  await fixture.whenStable(); // wait for the pending promises to resolve before proceeding
  const generatedId = "f9f64792-0ceb-4e3c-ae7b-4c7a8af6a552";
  httpTesting
    .expectOne({ method: "POST", url: "/urlB" })
    .flush({ id: generatedId });
  await fixture.whenStable(); // wait for the pending promises to resolve before proceeding
  const res = await req;
  expect(res.id).toEqual(generatedId);
  // call done to let Jasmine know you're done with this test
  done();
});

刷新一系列 Angular HTTP TestRequest

Flushing a sequence of Angular HTTP TestRequest

async-await

angular

angular-httpclient