Unit testing with private service injected using jasmine angular2

Or you can use jasmine.createSpyObj and provide it with useValue like bellow:

describe('YourComponent', () => {

  let serviceInjectedSpy: jasmine.SpyObj<ServiceInjected>;

  beforeEach(async(() => {

     // notice here
     serviceInjectedSpy = jasmine.createSpyObj('ServiceInjected', ['configure']);

     TestBed.configureTestingModule({
        declarations: [YourComponent],
        providers: [
           {provide: ServiceInjected, useValue: serviceInjectedSpy}
        ],
        imports: [
         ...
        ]
     }).compileComponents().then(() => {
        fixture = TestBed.createComponent(YourComponent);
        component = fixture.componentInstance;
     });
  });

  it('should assert my test', () => {
       serviceInjectedSpy.configure.and.returnValue(/* what you want */);
       component.init();
       expect(serviceInjectedSpy.configure).toHaveBeenCalled();
  });

});

You don't spy on the service tied to your TestBed. Get the service from your Testbed

beforeEach(() => {
  TestBed.configureTestingModule({
    providers: [ServiceToTest ,
      { provide: ServiceInjected, useValue: serviceInjectedStub }]
  });
  injectedService = TestBed.get(ServiceInjected);
});

And test on it

spyOn(injectedService, 'configure').and.returnValue(/* return same data type here */);
// ...
expect(injectedService.configure).toHaveBeenCalled();