Code coverage lines inside subscribe method in Angular 7

I have the following code and cannot test the lines in red, using Istanbul:

The test is the following, but no error is detected:

it('should set user info JSON to local storage after successful authentication', async(() => {
    component.loginForm.get('username').setValue('test');
    component.loginForm.get('passwd').setValue('test');

    spyOn(loginService, 'postLogin').and.returnValues(of({}));

    component.sendLoginForm();

    expect(component.loginFormSuccess).toEqual(true);
    expect(component.loginFormFail).toEqual(false);

    component.loggedInUserJSON = '{"login":"test","password":"test"}';
    localStorage.setItem('loggedInUserJSON', component.loggedInUserJSON);
    fakeLocalStorage.setItem('loggedInUserJSON', component.loggedInUserJSON);

    expect(localStorage.getItem('loggedInUserJSON')).toBe(component.loggedInUserJSON);
    expect(fakeLocalStorage.getItem('loggedInUserJSON')).toBe(component.loggedInUserJSON);

    expect(component.loggedInUserJSON).toBe('{"login":"test","password":"test"}');

    expect(component.postLoginObservable).toBeTruthy();
}));