Unit testing with default Angular installation

Unit testing with default Angular installation

Getting instance of a service

let mockedLoginService = TestBed.get(LoginService);

Asserting that some method is called

let spySomeMethod = spyOn(someInstance, 'someMethod');
 
// do something here
 
expect(spySomeMethod).toHaveBeenCalled();

Asserting that some method is called with given arguments

let spySomeMethod = spyOn(someInstance, 'someMethod').and.callFake((arg1, arg2) => {
  expect(arg1).toEqual(10);
  expect(arg2).toEqual(20);
});
 
// do something here
 
expect(spySomeMethod).toHaveBeenCalled();

Mocked Http Requests

1) Instead of using HttpClientModule, you should use HttpClientTestingModule. You will also use HttpTestingController. Below how to import and configure them:

...
import { HttpClientTestingModule, HttpTestingController } from "@angular/common/http/testing";
...
 
describe('YourClass', () => {
 
  beforeEach(() => {
    TestBed.configureTestingModule({
      imports:
        ...
        [ AppRoutingModule, HttpClientTestingModule ]
        ...
    });
  });
  ...
});