相关疑难解决方法(0)

我一直在寻找那些3:

主题,行为主体和重播主题.我想使用它们,知道何时以及为什么,使用它们有什么好处,虽然我已阅读文档,观看教程和搜索谷歌,但我没有对此有任何意义.

那他们的目的是什么？一个真实的案例将是非常感谢它甚至不必编码.

我更喜欢一个干净的解释,而不只是"a + b => c,你订阅了......"

谢谢

我有这个代码：

export class ProgramComponent implements OnInit {
   @Input() events: Observable<any>;
   eventsSubscription: any;
   ...
   ngOnInit() {
      this.eventsSubscription = this.events.subscribe((event) => {
          ... <- Some code that I want to test!!!!
          console.log("The test doesn't get past here!!!!");
      });
   }
}

describe('BLA BLA BLA', () => {
   let component: ProgramComponent;
   let fixture: ComponentFixture<ProgramComponent>;

   beforeEach(async(() => {
       TestBed.configureTestingModule({
          imports: [
              ...
          ],
          declarations: [ProgramComponent],
          providers: [
              ...
          ]
       }).compileComponents();
    }));

    beforeEach(() => {
       fixture = TestBed.createComponent(ProgramComponent);
       component = fixture.componentInstance;

       // HERE I WANT TO …