HttpTestingController does not resolve async/await

I’m submitting a…

[ ] Regression (a behavior that used to work and stopped working in a new release)
[x] Bug report  
[ ] Performance issue
[ ] Feature request
[ ] Documentation issue or request
[ ] Support request => Please do not submit support request here, instead see https://github.com/angular/angular/blob/master/CONTRIBUTING.md#question
[ ] Other... Please describe:

Current behavior

When using async await with promises (and therefore: this.http.get(...).toPromise()), one can unittest everything like normal with the HttpTestingController. BUT if you have a service method that has multiple await in it, the testing controller is not aware of the later executed await and will just wait and fail.

Expected behavior

All await calls inside a method should be executed during async testing.

Minimal reproduction of the problem with instructions

1. use a service with async await function like:

@Injectable()
class Service {
  constructor(private http: HttpClient){}
  public async foobar(): Promise<number> {
    await Promise.resolve();
    await Promise.resolve();
    await this.http.get('http://asdf').toPromise();
    return 1;
  }
}

1. try to use the HttpTestingClient to catch the http://asdf request.

Environment

Angular version: 6.1.0


Browser:
- [x ] Chrome (desktop) version XX
- [ ] Chrome (Android) version XX
- [ ] Chrome (iOS) version XX
- [ ] Firefox version XX
- [ ] Safari (desktop) version XX
- [ ] Safari (iOS) version XX
- [ ] IE version XX
- [ ] Edge version XX
 

[joshrizzo]

It works, you just have to make the call and then expect the call, and then await it:

    it('should return true and set the token', async () => {
      // Arrange
      const call = service.login('Test2', 'Password2', 'Local');
      const testToken = 'testToken';
      const loginRequest = httpMock.expectOne(environment.apiUrl + 'auth/login');
      loginRequest.flush(testToken);

      // Act
      const result = await call;

      // Assert
      httpMock.verify();
      expect(result).toBeTruthy();
      expect(service.authToken).toBe(testToken);
    });

[picolino]

Acceptable solution, but I would like to have a simplier solution, like this:

httpMock.addResponse(environment.apiUrl + 'auth/login', 'testToken');

const result = await service.login('Login', 'Password', 'Local');

expect(service.authToken).toBe(testToken);

The point is to define answers ahead the requests would be sent. I think that functionality must be out-of-the-box.