Angular 2:在组件浅层测试中用jasmine spy对象替换注入的渲染器

import { TestBed } from '@angular/core/testing';
import { MyComponent } from './my.component';

describe('MyComponent', () => {
  let component: MyComponent;

  beforeEach(() => {
    TestBed.configureTestingModule({
      declarations: [MyComponent],
      // providers: [Renderer] // 注释掉原来的注入渲染器的代码
    });

    component = TestBed.createComponent(MyComponent).componentInstance;
  });

  it('should do something', () => {
    const rendererSpy = jasmine.createSpyObj('Renderer', ['methodName']);
    // 使用spy对象替换注入的渲染器
    TestBed.overrideProvider(Renderer, { useValue: rendererSpy });

    // 在测试中使用spy对象
    component.someMethod();

    expect(rendererSpy.methodName).toHaveBeenCalled();
  });
});