describe("a banner component", () => {
    let component: BannerComponent;
    let fixture: ComponentFixture<BannerComponent>;
    let service: AuthenticationService;
    let sharedService: SharedService;
    let httpMock: HttpTestingController;

    // register all needed dependencies

    beforeEach(async () => {
        await TestBed.configureTestingModule({
        declarations: [BannerComponent],
        imports: [
            HttpClientTestingModule,
            RouterTestingModule
        ]
        }).compileComponents(); // compile template and css
    });

    beforeEach(() => {
        injector = getTestBed();
        // ways to get root injected service
        service = injector.get(AuthenticationService);
        httpMock = injector.get(HttpTestingController);


        fixture = TestBed.createComponent(ChangePasswordComponent);

        component = fixture.componentInstance;
        // to trigger changedetection so that template values updated
        fixture.detectChanges();

        // way to get component injected service
        authenticationService = fixture.debugElement.injector.get(
        AuthenticationService
        );
        sharedService = fixture.debugElement.injector.get(SharedService);
        h1 = fixture.nativeElement.querySelector("h1");
    });

    it("getHeaders: should get part headers", () => {
        service.getHeaders().subscribe(data => {
        expect(data).toEqual({});
        });
        const req = httpMock.expectOne(
        `www.test.com?userName=&roleId=&userId=&widgetTabKey=PART_CLASSIFICATION&tenantId=${service.env.environmentDetails.tenantId}&view=${API_SERVICE_CONSTANTS.WIDGET_SECTION.SUMMARY}&`
        );

        expect(req.request.method).toBe("POST");
        // will trigger flush to resolve all api response
        req.flush({});

        // verify if any pending request not completed
        httpMock.verify();
    });
  });