Angular 2 Jasmine 测试 Observable

Question

我正在测试一个调用服务的组件。我想存根或模拟服务，以便它返回一个布尔值，并且订阅函数的回调/成功函数中的组件变量设置为这个模拟的布尔值。因此，在我的组件中，从我的组件中调用了 welcomeService 中的 getBusinessDetails 方法，这就是我遇到问题的地方。我希望isReturning值被伪造，然后设置相应的组件变量。它返回 Expecte 未定义为真。

 public getBusinessDetails(): void {
        this.welcomeService.getBusiness(this.businessId, 2017)
            .subscribe((isReturning) => {
                this.isReturningApplicant = isReturning;
                this.welcomeMessage = this.isReturningApplicant ? 'Welcome Back' : 'Welcome';
            });
    }


TestBed.configureTestingModule({
            declarations: [WelcomeComponent],
            imports: [ReactiveFormsModule],
            providers: [{ provide: SessionService, useValue: sessionServiceStub },
            { provide: WelcomeService, useValue: welcomeServiceStub }]
        });

describe('Gets  details', () => {
        beforeEach(() => {
            sessionServiceStub = {
                getSession: function () { return { businessId: 11111, agentId: 11111 } }
            }
            welcomeServiceStub = {
                getBusiness: function () { return { subscribe: () => Observable.of(true) } }
            };
        })

        it('get a returning customer', () => {
            component.ngOnInit();
            expect(component.isReturningApplicant).toBe(true);

        });

    })

Answer 1

只要让它返回不带subscribe的可观察对象

getBusiness: function () { return Observable.of(true) }

返回的Observable 有subscribe 方法

getBusiness().subscribe()

getBusiness 返回Observable，然后您将调用更改为Observable.subscribe