Heroes: Setting up a HeroService stub for testing the container component

heroes.container.spec.ts

import { asapScheduler, of as observableOf } from 'rxjs';

import { femaleMarvelHeroes } from '../../test/female-marvel-heroes';
import { Hero } from '../hero';
import { HeroService } from '../hero.service';
import { HeroesContainerComponent } from './heroes.container';

describe(HeroesContainerComponent.name, () => {
  function createHeroServiceStub(): jasmine.SpyObj<HeroService> {
    const stub: jasmine.SpyObj<HeroService> = jasmine.createSpyObj(
      HeroService.name,
      [
        'addHero',
        'deleteHero',
        'getHeroes',
      ]);
    resetHeroServiceStub(stub);

    return stub;
  }

  function resetHeroServiceStub(stub: jasmine.SpyObj<HeroService>): void {
    stub.addHero
      .and.callFake(({ name }: Partial<Hero>) => observableOf({
        id: 42,
        name,
      }, asapScheduler))
      .calls.reset();
    stub.deleteHero
      .and.callFake((hero: Hero) => observableOf(hero, asapScheduler))
      .calls.reset();
    stub.getHeroes
      .and.returnValue(observableOf(femaleMarvelHeroes, asapScheduler))
      .calls.reset();
  }

  const heroServiceStub: jasmine.SpyObj<HeroService> = createHeroServiceStub();

  afterEach(() => {
    resetHeroServiceStub(heroServiceStub);
  });
});