如何在angular2中模拟一个activatedRoute父路由以进行测试？

问题描述

假设我有这个

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;
            });
        });
    }


}

我的组件是实际上工作得很好。问题是我想对它进行单元测试，但我无法弄清楚如何模拟 this.route.parent 对象。这是我的测试失败

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();
    });
});

测试失败并出现此错误

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

推荐答案

AcitvatedRoute是一个根据angular2的接口，所以我所做的是实现 MockActivatedRoute

AcitvatedRoute is an interface according to angular2 docs, so what I did is implements a MockActivatedRoute

import {Observable} from 'rxjs';
import {Type} from '@angular/core';
import {ActivatedRoute,Route,ActivatedRouteSnapshot,UrlSegment,Params,Data } from '@angular/router';

export class MockActivatedRoute implements ActivatedRoute{
    snapshot : ActivatedRouteSnapshot;
    url : Observable<UrlSegment[]>;
    params : Observable<Params>;
    queryParams : Observable<Params>;
    fragment : Observable<string>;
    data : Observable<Data>;
    outlet : string;
    component : Type<any>|string;
    routeConfig : Route;
    root : ActivatedRoute;
    parent : ActivatedRoute;
    firstChild : ActivatedRoute;
    children : ActivatedRoute[];
    pathFromRoot : ActivatedRoute[];
    toString() : string{
        return "";
    };
}

只需更换 ActivatedRoute 在我的测试中 MockActivatedRoute 像这样

and just replace the ActivatedRoute in my tests for MockActivatedRoute like this

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

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

这篇关于如何在angular2中模拟一个activatedRoute父路由以进行测试？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！