Angular 2(Mock Ionic2) - 没有App的提供者

Question

我正在尝试spec.ts为我的应用程序创建一个.可悲的是这是使用LoadingController从ionic-angular.现在,当我尝试配置模块时,我需要为它提供LoadingController(因为它在模块的构造函数中).

我目前遇到的问题是LoadingController想要提供一个App对象/实例.(_app: App参数)

我很绝望,所以我自己问了Ionic.github#8539

但是他们关闭了我的问题,因为这是一个问题,而不是一个问题,尽管我遇到了一些他们没有回应的问题.如果这是不可能的/没有人知道如何将是一个耻辱,因为它是一个非常酷的功能,它不仅影响LoadingController,因此AlertController和ToastController也受此影响.

我的testbed配置atm:

TestBed.configureTestingModule({
    declarations: [EventsPage],
    schemas: [CUSTOM_ELEMENTS_SCHEMA],
    providers: [
      {provide: APICaller, useValue: mockAPICaller},
      {provide: NavController, useValue: mockNavController },
      {provide: LoadingController, useValue: ???????}, //it seems like everything I try to enter here fails.
    ],
    imports: [FormsModule]
  });

和EventsPage构造函数:

constructor(public apiCaller: APICaller, public navCtrl: NavController,
             public loadingCtrl: LoadingController){}

编辑:LoadingController的用法

getEvents() {
    // setup a loadingscreen
     let loading = this.loadingCtrl.create({
      content: "Loading..."
    }); 
   // present the loadingscreen
    loading.present();

    // reset the noEvents boolean.
    this.noEvents = true;

    // call the api and get all events
    this.apiCaller.getEvents()
    .subscribe(response => {
      // response is list of events
      this.events = response;
      // if the event is not empty, set noEvents to false.
      if (this.events.length > 0) {
        this.noEvents = false;
      }
      // close the loading message.
     loading.dismiss();
    });
  }

然后将导致此loadingspinner(具有不同的文本)

Answer 1

有了这种类型的东西,你可能不想在UI中测试任何东西(关于使用它LoadingController).您应该测试的是组件的行为.因此,当你为LoadingController你想要做的事情创建模拟时,会监视关键方法,并且你的期望应该进行测试,以确保你在调用方法LoadingController.这样做可以编写类似的测试

expect(loadingController.someMethod).toHaveBeenCalled();
// or
expect(loadingController.someMethod).toHaveBeenCalledWith(args);

你的模拟不必遵循被模拟的项目的实际结构.例如,LoadingController.create返回一个Loading对象.在你的模拟中,你不需要这个.如果你想要,你可以在调用时返回模拟本身create,并且在模拟中只需要具有的方法Loading.

请记住,您只是在测试控制器的行为.模拟LoadingController实际上做了什么并不重要,只是你能够调用方法,并检查测试以确保它们在被调用时被调用.除此之外,你应该假设真实的LoadingController作品.

所以你可以有类似的东西

let mockLoadingController = {
  // Tried `create: jasmine.createSpy('create').and.returnValue(this)
  // seem this doesn't work. We just create the spy later
  create: (args: any) => { return this; },
  present: jasmine.createSpy('present'),
  dismiss: jasmine.createSpy('dismiss')
};
spyOn(mockLoadingController, 'create').and.returnValue(mockLoadingController);

{ provide: LoadingController, useValue: mockLoadingController }

然后在你测试中你可以做类似的事情

it('should create loader with args ...', () => {
  ...
  expect(mockLoadingController.create).toHaveBeenCalledWith({...})
})
it('should present the loader', () => {
  ...
  expect(mockLoadingController.present).toHaveBeenCalled();
})
it('should dismiss the loader when the api call returns', async(() => {
  ..
  expect(mockLoadingController.dismiss).toHaveBeenCalled();
}))

这是我现在用来测试的

class LoadingController {
  create(args: any) { return this; }
  present() {}
  dismiss() {}
}

@Component({
  template: ''
})
class TestComponent {
  constructor(private loadingController: LoadingController) {}

  setEvents() {
    let loading = this.loadingController.create({hello: 'world'});

    loading.present();
    loading.dismiss();
  }
}

describe('component: TestComponent', () => {
  let mockLoadingController;

  beforeEach(async(() => {
    mockLoadingController = {
      create: (args: any) => { return this; },
      present: jasmine.createSpy('present'),
      dismiss: jasmine.createSpy('dismiss')
    };
    spyOn(mockLoadingController, 'create').and.returnValue(mockLoadingController);

    TestBed.configureTestingModule({
      declarations: [TestComponent],
      providers: [
        { provide: LoadingController, useValue: mockLoadingController }
      ]
    });
  }));

  it('should calling loading controller', () => {
    let comp = TestBed.createComponent(TestComponent).componentInstance;
    comp.setEvents();

    expect(mockLoadingController.create).toHaveBeenCalledWith({ hello: 'world'});
    expect(mockLoadingController.present).toHaveBeenCalled();
    expect(mockLoadingController.dismiss).toHaveBeenCalled();
  });
});

也可以看看:

• 关于间谍的Jasmine文档