Testing To do service with HttpMock installed

todo.service.spec.ts

fdescribe('TodoService', () => {
  let service: TodoService;
  let httpMock: HttpTestingController;

  beforeEach(() => {
    TestBed.configureTestingModule({
      imports: [HttpClientTestingModule]
    });
    service = TestBed.inject(TodoService);
    httpMock = TestBed.inject(HttpTestingController);
  });
  
  afterEach(() => {
    httpMock.verify();
  })

  it('should be created', () => {
    expect(service).toBeTruthy();
  });
});