如何在ngOninit中编写订阅块的Jasmine测试用例，并传递一些虚拟数据？

npm install --save-dev jasmine karma karma-jasmine karma-chrome-launcher

import { ExampleComponent } from './example.component';
import { DataService } from './data.service';
import { of } from 'rxjs';

describe('ExampleComponent', () => {
  let component: ExampleComponent;
  let dataService: DataService;

  beforeEach(() => {
    dataService = jasmine.createSpyObj('DataService', ['getData']);
    component = new ExampleComponent(dataService);
  });

  it('should subscribe to data on ngOnInit', () => {
    const testData = [1, 2, 3]; // 虚拟数据
    (dataService.getData as jasmine.Spy).and.returnValue(of(testData));

    component.ngOnInit();

    expect(component.data).toEqual(testData);
  });
});

ng test