Jasmine单元测试 - 无法读取未定义的属性管道

Question

我使用的是Angular 6,NgRx 6,RxJS 6.

我有一个看起来像这样的护卫员 -

import { CanActivate, ActivatedRouteSnapshot } from '@angular/router';
import { Injectable } from '@angular/core';
import { Observable, of } from 'rxjs';
import { IAppState } from '../../../app.state';
import { Store } from '@ngrx/store';

import { SetTenant } from './../../../store/config/config.actions';

@Injectable()
export default class TenantGuard implements CanActivate {
  constructor(private store: Store<IAppState>) {}

  canActivate(route: ActivatedRouteSnapshot): Observable<boolean> {
    const tenant = route.params['tenant'];

    if (!tenant) {
      return of(false);
    }

    this.store.dispatch(new SetTenant(tenant));
    return of(true);
  }
}

正如你所看到的,我正在通过tenant商店将我添加到商店this.store.dispatch(new SetTenant(tenant));

然而,这导致每次用户访问基本路线时都会触发该动作.

为了解决这个问题,我添加了一个检查,看看是否tenant已填充,如果没有,则仅触发操作 -

import { CanActivate, ActivatedRouteSnapshot } from '@angular/router';
import { Injectable } from '@angular/core';
import { Observable, of, combineLatest } from 'rxjs';
import { IAppState } from '../../../app.state';
import { Store, select } from '@ngrx/store';

import { SetTenant } from './../../../store/config/config.actions';
import { getTenant } from '../../../store/config/config.selectors';
import { map } from 'rxjs/operators';

@Injectable()
export default class TenantGuard implements CanActivate {
  constructor(private store: Store<IAppState>) {}

  canActivate(route: ActivatedRouteSnapshot): Observable<boolean> {
    const tenantFromRoute: string = route.params['tenant'];

    return this.store.pipe(select(getTenant)).pipe(
      map(tenantFromStore => {
        if (!tenantFromRoute) {
          return false;
        }

        if (!tenantFromStore) {
          this.store.dispatch(new SetTenant(tenantFromRoute));
        }
        return true;
      })
    );
  }
}

然而,这已经破坏了我的单元测试,因为我已经引入了额外的逻辑,现在我收到了错误 TypeError: Cannot read property 'pipe' of undefined

我的spec文件看起来像这样 -

import { TestBed, async } from '@angular/core/testing';
import { CUSTOM_ELEMENTS_SCHEMA } from '@angular/core';
import { Store } from '@ngrx/store';
import { StoreModule } from '@ngrx/store';

import { SetTenant } from './../../../store/config/config.actions';

import TenantGuard from './tenant.guard';

describe('TenantGuard', () => {
  it('should return false if a tenant is not present on the route', async(() => {
    const { tenantGuard, props } = setup({});
    let result: boolean;
    tenantGuard.canActivate(props).subscribe(canActivate => (result = canActivate));
    expect(result).toBeFalsy();
  }));

  it('should return true if a tenant is present on the route', async(() => {
    const { tenantGuard, props } = setup({ tenant: 'main' });
    let result: boolean;
    tenantGuard.canActivate(props).subscribe(canActivate => (result = canActivate));
    expect(result).toBeTruthy();
  }));

  it('should dispatch an action to set the tenant in the store', () => {
    const { store, tenantGuard, props } = setup({ tenant: 'foo' });
    const action = new SetTenant('foo');
    tenantGuard.canActivate(props);

    expect(store.dispatch).toHaveBeenCalledWith(action);
  });

  it('should not dispatch an action to set the tenant in the store if the tenant is missing', () => {
    const { store, tenantGuard, props } = setup({});
    tenantGuard.canActivate(props);

    expect(store.dispatch).not.toHaveBeenCalled();
  });

  const setup = propOverrides => {
    TestBed.configureTestingModule({
      imports: [StoreModule.forRoot({})],
      providers: [
        TenantGuard,
        {
          provide: Store,
          useValue: jasmine.createSpyObj('Store', ['dispatch', 'pipe']),
        },
      ],
      schemas: [CUSTOM_ELEMENTS_SCHEMA],
    }).compileComponents();

    const props = Object.assign({ params: { tenant: null } }, { params: { ...propOverrides } });

    const tenantGuard = TestBed.get(TenantGuard);
    const store = TestBed.get(Store);

    return { tenantGuard, props, store };
  };
});

我已经加入pipe了我,jasmine.createSpyObj但我不确定如何进步.

我想围绕这个编写额外的测试,但是在模拟出pipe在这种情况下应该/将如何使用时遇到了麻烦.

编辑 - 如果我没有传入pipe我的jasmine.createSpyObjI而是得到错误??TypeError: this.store.pipe is not a function??

Answer 1

我和你有同样的错误信息。我将路由器注入到组件中并使用了 this.router.events.pipe(...)... 我在测试中使用了路由器的存根。在 routerStub 之前看起来像这样：

routerStub = {
        navigate: (commands: any[]) => { Promise.resolve(true); },
};

所以你可以看到，在我的组件中需要路由器的导航方法之前，我在存根中定义了它。现在我还需要 events 属性，它返回一个使用 .pipe 的可观察值。我在 routerStub 中添加了以下内容，它为我解决了这个问题：

routerStub = {
        navigate: (commands: any[]) => { Promise.resolve(true); },
        events: of(new Scroll(new NavigationEnd(0, 'dummyUrl', 'dummyUrl'), [0, 0], 'dummyString'))
};

就我而言，我需要一个滚动事件才能使我的代码正常工作，但现在事件在我的存根中被定义为可观察的，并且现在管道是已知的。

也许这对你有帮助...