Mocking Providers

For every Spectator factory, we can easily mock any provider.

Every service that we pass to the mocks property will be mocked using the mockProvider() function. The mockProvider() function converts each method into a Jasmine spy. (i.e jasmine.createSpy()).

Here are some of the methods it exposes:

dateService.isExpired.and.callThrough();
dateService.isExpired.and.callFake(() => fake);
dateService.isExpired.and.throwError('Error');
dateService.isExpired.andCallFake(() => fake);

However, if you use Jest as test framework and you want to utilize its mocking mechanism instead, import the mockProvider() from @openng/spectator/jest. This will automatically use the jest.fn() function to create a Jest compatible mock instead.

mockProvider() doesn’t include properties. In case you need to have properties on your mock you can use 2nd argument:

const createService = createServiceFactory({
  service: AuthService,
  providers: [
    mockProvider(OtherService, {
      name: 'Martin',
      emitter: new Subject(),
      mockedMethod: () => 'mocked'
    })
  ],
});