Angular - 用于 Jasmine 单元测试的模拟 Promise 方法

Question

测试方法

  public onSubmit(registerData: RegisterDataModel): void {
    this.registrationService.registerWithEmailAndPassword(registerData).then((msg: string[]) =>
      this.router.navigate(['/completeSignUp']).then(() => {
        msg.forEach(singleMessage => this.notificationService.primary(singleMessage));
      }))
      .catch((msg) => msg.forEach(singleMessage => {
        this.notificationService.danger(singleMessage);
      }));
  }

我想测试是否在我的方法中调用了 router.navigate。现在我想模拟我的 service.registerWithEmailAndPasswort Promise 但不知何故我无法模拟它。

我的规范文件

//Stubs
const routerStub: Router = jasmine.createSpyObj('Router', ['navigate']);
const registryStub: RegistrationService = jasmine.createSpyObj('RegistrationService', ['registerWithEmailAndPassword']);

单元测试

  it('should navigate on promise - success', () => {
    (<jasmine.Spy>registryStub.registerWithEmailAndPassword).and.callThrough();
    const spy = (<jasmine.Spy>routerStub.navigate);
    component.onSubmit({username: null, email: null, password: null, passwordConfirm: null, termsAndCondition: null});
    expect(spy).toHaveBeenCalledWith(['/completeSignUp']);
  });

出现的错误是:TypeError: Cannot read property 'then' of undefined有人知道如何正确模拟此服务吗？

编辑

我也试过像这样 mock 这个 promise :

    (<jasmine.Spy>registryStub.registerWithEmailAndPassword)
  .and.returnValue(new Promise(() => Promise.resolve()));

但它仍然让我感到震惊:

Expected spy Router.navigate to have been called with [ [ '/completeSignUp' ] ] but it was never called.

Answer 1

正如 silicon Soul 提到的，您肯定需要模拟 router.navigate promise 返回值，否则它将进入 Promise.reject() .通过添加 (<jasmine.Spy>routerStub.navigate).and.returnValue(Promise.resolve());单元测试应该没问题。最终的单元测试应如下所示:

  it('should navigate on promise - success', fakeAsync(() => {
    const spy = (<jasmine.Spy>routerStub.navigate).and.returnValue(Promise.resolve());
    (<jasmine.Spy>registryStub.registerWithEmailAndPassword).and.returnValue(Promise.resolve(['test']));
    component.onSubmit({username: 'test', email: 'test', password: 'test', passwordConfirm: 'test', termsAndCondition: true});

    tick();
    expect(spy).toHaveBeenCalledWith(['/completeSignUp']);
  }));