How to mock an activatedRoute parent Route in angular2 for testing purposes?

Question

Let's say I have this

export class QuestionnaireQuestionsComponent {

    questions: Question[] = [];
    private loading:boolean = true;


    constructor(
        private route: ActivatedRoute,
        public questionnaireService:QuestionnaireService) {}

    ngOnInit(){
        this.route.parent.params.subscribe((params:any)=>{
            this.questionnaireService.getQuestionsForQuestionnaire(params.id).subscribe((questions)=>{
                this.questions = questions;
                this.loading = false;
            });
        });
    }


}

My component is actually working pretty well. Problem is that I want to unit test it but I can't figure out how to mock the this.route.parent object. Here's my test that fails

beforeEach(()=>{
    route = new ActivatedRoute();
    route.parent.params = Observable.of({id:"testId"});

    questionnaireService = jasmine.createSpyObj('QuestionnaireService', ['getQuestionsForQuestionnaire']);
    questionnaireService.getQuestionsForQuestionnaire.and.callFake(() => Observable.of(undefined));
    component = new QuestionnaireQuestionsComponent(route, questionnaireService);
});


describe("on init", ()=>{
    it("must call the service get questions for questionnaire",()=>{
        component.ngOnInit();
        expect(questionnaireService.getQuestionsForQuestionnaire).toHaveBeenCalled();
    });  
});

The test fails with this error

TypeError: undefined is not an object (evaluating 'this._routerState.parent') 

Answer 1

Using TestBed

 beforeEach(async(() => {
    TestBed.configureTestingModule({
      declarations: [YourComponent],
      imports: [],
      providers: [
        {
          provide: ActivatedRoute, useValue: {
            params: Observable.of({ id: 'test' })
          }
        }
      ]
    })
      .compileComponents();
  }));