Unit testing with private service injected using jasmine angular2

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();

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();  });});

Use this:

spyOn(serviceInjectedStub, 'configure').and.returnValue(config); // config is a mock