NgRx效果:单元测试-似乎操作永远不会产生效果

import { TestBed } from '@angular/core/testing';
import { provideMockActions } from '@ngrx/effects/testing';
import { Observable, of } from 'rxjs';
import { TestScheduler } from 'rxjs/testing';

import { MyEffect } from './my.effect';
import { MyService } from './my.service';
import { MyAction, MySuccessAction } from './my.actions';

describe('MyEffect', () => {
  let effect: MyEffect;
  let actions$: Observable<any>;
  let myService: jasmine.SpyObj<MyService>;
  let scheduler: TestScheduler;

  beforeEach(() => {
    const spy = jasmine.createSpyObj('MyService', ['getData']);
    TestBed.configureTestingModule({
      providers: [
        MyEffect,
        provideMockActions(() => actions$),
        { provide: MyService, useValue: spy }
      ]
    });
    effect = TestBed.inject(MyEffect);
    actions$ = TestBed.inject(Actions);
    myService = TestBed.inject(MyService) as jasmine.SpyObj<MyService>;
    scheduler = new TestScheduler((actual, expected) => {
      expect(actual).toEqual(expected);
    });
  });

  it('should dispatch MySuccessAction on successful data retrieval', () => {
    const data = { id: 1, name: 'Test' };
    const action = new MyAction();
    const completion = new MySuccessAction(data);

    scheduler.run(({ hot, cold, expectObservable }) => {
      actions$ = hot('-a', { a: action });
      myService.getData.and.returnValue(of(data));

      expectObservable(effect.myEffect$).toBe('--b', { b: completion });
    });
  });
});