create test for activatedRoute data

Question

I want to create test for my component. I have router resolver that resolve data and read data in ng init .i want create test for that .How can i create test for this code

    @Component({
    selector: 'jhi-label-detail',
    templateUrl: './label-detail.component.html'
})
export class LabelDetailComponent implements OnInit {

    label: Label;

    constructor(
        private route: ActivatedRoute
    ) {
    }

    ngOnInit() {
        this.route.data.subscribe(({label}) => {
            this.label = label.body ? label.body : label;
        });
    }


}

and route is like this

{
        path: 'label/:id/view',
        component: LabelDetailComponent,
        resolve: {
            label: LabelResolve
        }
    }

and resolve is this

@Injectable()
export class LabelResolve implements Resolve<any> {

    constructor(private service: LabelService) {
    }

    resolve(route: ActivatedRouteSnapshot, state: RouterStateSnapshot) {
        const id = route.params['id'] ? route.params['id'] : null;
        if (id) {
            return this.service.find(id);
        }
        return new Label();
    }

}

Answer 1

import { async, ComponentFixture, TestBed } from '@angular/core/testing';
import { ActivatedRoute } from '@angular/router';
import { of } from 'rxjs/observable/of';
import { Observable } from 'rxjs/Observable';

import { MyComponent } from './my-component.component';

describe('MyComponent', () => {
  let component: MyComponent;
  let fixture: ComponentFixture<MyComponent>;
  const route = ({ data: of({ label: 'hello' }) } as any) as ActivatedRoute;

  beforeEach(
    async(() => {
      TestBed.configureTestingModule({
        declarations: [MyComponent],
        providers: [{ provide: ActivatedRoute, useValue: route }],
      }).compileComponents();
    }),
  );

  beforeEach(() => {
    fixture = TestBed.createComponent(MyComponent);
    component = fixture.componentInstance;
    fixture.detectChanges();
  });

  it('should set the label', () => {
    expect(component.label).toEqual('hello');
  });
});

The important thing to note here is that we are providing our own implementation of ActivatedRoute in TestBed.providers, with just one property (data) that is being used by our component.