Heroes: Testing deletion of a hero

heroes.container.spec.ts

describe('deletes a hero', () => {
  it(`delegates to ${HeroService.name}`, () => {
    const gamora: Hero = femaleMarvelHeroes.find(x => x.name === 'Gamora');

    container.delete(gamora);

    expect(heroServiceStub.deleteHero).toHaveBeenCalledTimes(1);
    expect(heroServiceStub.deleteHero).toHaveBeenCalledWith(gamora);
  });
});