Ggtcf

I'm trying to unit test Resolver service in Angular. One of my test cases is setting value by transferState (Server Side Rendering). I gonna do it in pipe of getHomePageData Observable. Notice, I mocked what that method is returning.

I'm trying to harness fakeAsync to it. Calling `flush()' (earlier tried tick()) I expected it to get into pipe, but it doesn't. What am I doing wrong here?

import Injectable, Inject, PLATFORM_ID from '@angular/core';
import Resolve from '@angular/router';
import makeStateKey, TransferState, StateKey from '@angular/platform-browser';
import isPlatformServer from '@angular/common';


import Observable, of from 'rxjs';
import tap from 'rxjs/operators';


import ScienceStoryService from '../../core/science-story/science-story.service';
import HomePage from './home-page';


@Injectable()
export class HomePageResolveService implements Resolve<HomePage> 


 constructor(private readonly scienceStoryService: ScienceStoryService,
 @Inject(PLATFORM_ID) private readonly platformId,
 private readonly transferState: TransferState) 


 resolve(): Observable<HomePage> 
 const HOMEPAGE_DATA_KEY: StateKey<HomePage> = this.getStateKey('homepage-data');


 if (this.transferState.hasKey(HOMEPAGE_DATA_KEY)) 
 const homePageData = this.transferState.get<HomePage>(HOMEPAGE_DATA_KEY, null);
 this.transferState.remove(HOMEPAGE_DATA_KEY);


 return of(homePageData);
 else 
 return this.scienceStoryService.getHomePageData()
 .pipe(
 tap((homePageData: HomePage) => 
 if (this.isPlatformServer()) 
 this.transferState.set(HOMEPAGE_DATA_KEY, homePageData);
 
 )
 );
 
 


 getStateKey(keyName: string): StateKey<HomePage> 
 return makeStateKey<HomePage>(keyName);
 


 isPlatformServer(): boolean 
 return isPlatformServer(this.platformId);
 

Unit test:

it('should set transfer state while running on server', fakeAsync(() => 
 spyOn(service, 'getStateKey').and.returnValue(makeStateKey<HomePage>('non-existing-key'));
 const scienceStoryService = TestBed.get(ScienceStoryService);
 spyOn(scienceStoryService, 'getHomePageData').and.returnValue(of());
 const transferState = TestBed.get(TransferState);
 spyOn(service, 'isPlatformServer').and.returnValue(true);
 spyOn(transferState, 'set');
 service.resolve();
 flush();
 expect(transferState.set).toHaveBeenCalledTimes(1);
 ));