Testing simple Get request

todo.service.spec.ts

it('getSingleTodo should send a GET request and return a single item', (done) => {

    service.getSingleTodo(1).subscribe(
      (item: Todo) => { expect(item).toBeDefined(); done(); },
      (error) => { fail(error.message) }
    );

    const testRequest = httpMock.expectOne('https://jsonplaceholder.typicode.com/todos/1');
    expect(testRequest.request.method).toBe('GET');
    testRequest.flush({ id: 1, userId: 1, title: 'Test Todo', completed: false });
   
});