Angular单元测试MockService仍然抛出不能读取未定义属性'subscribe‘的异常

// 引入需要使用的依赖
import { TestBed } from '@angular/core/testing';
import { YourComponent } from './your.component';
import { YourService } from './your.service';

describe('YourComponent', () => {
  let component: YourComponent;
  let service: jasmine.SpyObj<YourService>;

  beforeEach(() => {
    // 创建虚拟的服务实例
    const spy = jasmine.createSpyObj('YourService', ['yourMethod']);
    
    TestBed.configureTestingModule({
      declarations: [YourComponent],
      providers: [{ provide: YourService, useValue: spy }]
    });

    // 获取组件和服务实例
    component = TestBed.createComponent(YourComponent).componentInstance;
    service = TestBed.inject(YourService) as jasmine.SpyObj<YourService>;
  });

  it('should do something', () => {
    // 设置虚拟服务的返回值
    service.yourMethod.and.returnValue('mocked value');

    // 调用被测试组件的方法
    component.yourMethod();

    // 验证预期的行为和结果
    expect(service.yourMethod).toHaveBeenCalled();
    expect(component.someProperty).toBe('mocked value');
  });
});