等待 Jasmine 的变量总是未定义

Question

我需要测试一个函数，在该函数中创建了一个变量并为其赋值。

但是有效负载常量始终未定义。

活动-card.component.ts

async ngOnInit() {
    const { uid } = await this.auth.currentUser
    const { payload } = await this.firestore.surveysUsers(this.survey.id).doc(uid).snapshotChanges().pipe(first()).toPromise();
    this.completed = payload.exists
  }

分量-card.component.spec.ts

beforeEach(waitForAsync(() => {
    fireStoreServiceMock.surveysUsers.and.returnValue({ 
      doc: () => { return {
        snapshotChanges: () => { return {
          pipe: () => { return {
            toPromise: () => { return { exists: true }}
          }}
        }}
      }}
    });
  }));

describe('tests in delete', () => {
    it('should update surveys', fakeAsync(() => {
      fixture.detectChanges();
      component.delete().then(() => {
      });
      fixture.detectChanges();
      tick();

      expect(fireStoreServiceMock.surveys).toHaveBeenCalled();
      expect(snackBarMock.open).toHaveBeenCalled();
    }));
  });

错误

Error: Uncaught (in promise): TypeError: Cannot read property 'exists' of undefined
TypeError: Cannot read property 'exists' of undefined
    at CampaignsCardComponent.<anonymous> (http://localhost:9876/_karma_webpack_/webpack:/src/app/modules/campaigns/pages/campaigns-card/campaigns-card.component.ts:43:4)
    at Generator.next (<anonymous>)
    at fulfilled (http://localhost:9876/_karma_webpack_/webpack:/node_modules/tslib/tslib.es6.js:71:42)
    at ZoneDelegate.invoke (http://localhost:9876/_karma_webpack_/webpack:/node_modules/zone.js/dist/zone-evergreen.js:372:1)
    at ProxyZoneSpec.onInvoke (http://localhost:9876/_karma_webpack_/webpack:/node_modules/zone.js/dist/proxy.js:126:1)
    at ZoneDelegate.invoke (http://localhost:9876/_karma_webpack_/webpack:/node_modules/zone.js/dist/zone-evergreen.js:371:1)
    at Object.onInvoke (http://localhost:9876/_karma_webpack_/webpack:/node_modules/@angular/core/fesm2015/core.js:28535:1)
    at ZoneDelegate.invoke (http://localhost:9876/_karma_webpack_/webpack:/node_modules/zone.js/dist/zone-evergreen.js:371:1)
    at Zone.run (http://localhost:9876/_karma_webpack_/webpack:/node_modules/zone.js/dist/zone-evergreen.js:134:1)
    at http://localhost:9876/_karma_webpack_/webpack:/node_modules/zone.js/dist/zone-evergreen.js:1276:1

Answer 1

快到了。问题是这是一个可观察的对象，你不应该在其上模拟 pipe 函数，而是 return 一个来自函数调用的可观察对象。

试试这个：

import { of } from 'rxjs';
....
beforeEach(waitForAsync(() => {
    fireStoreServiceMock.surveysUsers.and.returnValue({ 
      doc: () => { return {
        snapshotChanges: () => of({ exists: true }) // mock the observable with of
        }}
      }}
    });
  }));

我可能把括号 ({ }) 搞乱了，但应该可以了。

等待 Jasmine 的变量总是未定义

Variable always undefined with await Jasmine

jasmine

typescript

karma-jasmine

angular