我有这个试图模拟的 Angular 服务：@Injectable({ providedIn: 'root',})export class NotificationsService { private _notifications = new Subject
我正在尝试模拟这个 Angular 服务：
@Injectable({
providedIn: 'root',
})
export class NotificationsService {
private _notifications = new Subject<Notification>();
public notifications: Observable<Notification> = this._notifications.asObservable();
public crudNotifications: Observable<CrudNotification> = this._notifications.asObservable().pipe(
filter(notification => notification.notificationType === 'crud-notification'),
map(notification => notification as CrudNotification)
);
//....
}
我刚刚将其迁移到 Jest，并试图弄清楚当我的测试服务尝试访问时如何模拟返回自定义可观察对象 NotificationsService.crudNotifications
目前，我有这个：
describe('OrganizationUsersService', () => {
let organizationUsersService: OrganizationUsersService;
let crudNotifications!: Subject<CrudNotification>;
let notificationServiceMock!: Spy<NotificationsService>
let storeMock!: Spy<Store>;
let httpTestingController! :HttpTestingController;
beforeEach(()=>{
TestBed.configureTestingModule({
providers:[
{provide: NotificationsService, useValue: createSpyFromClass(NotificationsService)},
{provide: Store, useValue: createSpyFromClass(Store) },
{provide: Router, useValue: createSpyFromClass(Router) },
provideHttpClient(),
provideHttpClientTesting(),
]
})
httpTestingController = TestBed.inject(HttpTestingController);
notificationServiceMock = TestBed.inject<any>(NotificationsService);
storeMock = TestBed.inject<any>(Store);
//Common mocked stuff behavior for every methods here
crudNotifications = new Subject<CrudNotification>();
notificationServiceMock.crudNotifications = crudNotifications.asObservable();
storeMock.dispatch.mockReturnValue(of());
storeMock.select.mockReturnValue(of({ id: 'some-id' }));
//Finally create the service to test:
organizationUsersService = TestBed.inject(OrganizationUsersService);
})
fit('should refresh the store when the backend inform a new role attribution has been added for the current organization id', fakeAsync(() => {
//Arrange
organizationUsersService.initialize(); //Required to register
//Act
crudNotifications.next({
dataType: 'organization.role-attribution',
operationType: 'add',
id: 'some-id',
notificationType: 'crud-notification',
});
tick();
//Assert
httpTestingController.expectOne(environment.backendUrl + 'some/stuff').flush({});
httpTestingController.expectOne(environment.backendUrl + 'some/other/stuff').flush({});
expect(storeMock.dispatch).toHaveBeenCalledWith(expect.any(SetLoadingAction));
organizationUsersService.dispose();
}));
}));
这不起作用，因为我尝试设置的可观察对象没有启用 Spy 方法。我尝试过这个：
notificationServiceMock.crudNotifications.mockReturnValue(crudNotifications);
但公共字段上不存在 mockReturnValue 方法。
有没有办法在公共领域模拟价值？
我看到您使用了 \'subscribe\'，这意味着 RxJS。您可以使用 lastValueFrom 函数将您的可观察对象转换为承诺。
import { lastValueFrom } from 'rxjs'
async GetAdditionalProducts() {
return lastValueFrom(this.proposalService.getProductList(this.filter))
}
如果您想自己实现，您可以将您的 this.proposalService.getProductList(this.filter) 调用包装成一个承诺，然后在您的“订阅”回调中解决该承诺。
您传递给 Promise 的任何内容都 resolve 将成为您的承诺的返回值，并且在使用 await 函数时可以访问。
async GetAdditionalProducts() {
return new Promise(resolve => {
this.proposalService.getProductList(this.filter).subscribe(response => {
resolve(response.productList);
});
})
}
然后，您可以致电 GetAdditionalProducts 并等待回复。
async onSearch() {
this.additionalProducts = await this.GetAdditionalProducts();
}
编辑：将可观察对象转换为承诺的新标准似乎是 lastValueFrom 。我已编辑了我的答案。感谢 Bojan 指出这一点。