Angular2: Unit testing a component with Route resolve

I have a component that depends on a data from Route Resolve. Following is the code snippet of the router

           {
                path: 'attachment',
                component: SgCreateAttachmentComponent,
                resolve: {
                    referenceData: SgCreateAttachmentResolve
                },
                data: {
                    'seq' : 5
                },
                canActivate: [SgCreateCanActivateGaurd]
            }

Inside the component I fetch the resolve data inside ngOnInit.

ngOnInit() {

    this.standardAttachmentCategories = this._activatedRoute.snapshot.data['referenceData'].json();

   }

I am trying to unit test the ngOnInit function of the component. Following is a code snippet from my spec.

it('should ensure ngOnInit is called', () => {
    fixture.detectChanges();
});

Also, i have the following configuration of the test bed

beforeEach(async(() => {

        TestBed.configureTestingModule({
            imports: [HttpModule, SgCreateModule],
            providers: [FormBuilder, { provide: SgCreateService, useClass: SgCreateMockService },
                { provide: SgCreateAttachmentService, useClass: SgCreateAttachmentServiceMock },
                SgCreateModelService,
                { provide: Router, useClass: RouterStub },
                  { provide: ActivatedRoute, useClass: ActivatedRouteStub },
                { provide: XHRBackend, useClass: MockBackend }
            ]
        })
            .compileComponents();
        fixture = TestBed.createComponent(SgCreateAttachmentComponent);
        comp = fixture.componentInstance;



    }));

But, executing the above test throws error:

Cannot read property 'referenceData' of undefined

I have also tried the following

  it('should ensure ngOnInit is called', () => {
        const activatedRouteStub = fixture.debugElement.injector.get(ActivatedRoute);
        activatedRouteStub.testParams = { data: new Response() };
        fixture.detectChanges();
    });

But i am facing the same issue.