测试依赖于路由参数的组件

Question

我有一个关于在 angular2 中测试路由组件的问题。

这是一个简单的组件，它依赖于带有参数 'foo' 的路由。组件中的属性 foo 将被设置为参数的值。

import {Component, OnInit} from '@angular/core';
import {ActivatedRoute, Params} from '@angular/router';

@Component({
    selector: 'my-component',
    templateUrl: './my-component.html'
})
export class MyComponent implements OnInit
{
    foo: string;

    constructor(
        private route: ActivatedRoute
    )
    {
    }

    ngOnInit()
    {
        this.route.params.subscribe((params: Params) => {
            this.foo = params['foo'];
        });
    }
}

现在我想测试一下，如果使用路由创建组件，参数设置是否正确。所以我想在某个地方 expect(component.foo).toBe('3');.

import {TestBed, ComponentFixture, async} from '@angular/core/testing';
import {DebugElement} from '@angular/core';
import {By} from '@angular/platform-browser';
import {Params, ActivatedRoute} from '@angular/router';

import {Observable} from 'rxjs';

import {MyComponent} from './MyComponent';

describe('MyComponent', () => {
    let mockParams, mockActivatedRoute;

    let component: MyComponent;
    let fixture: ComponentFixture<MyComponent>;
    let debugElement: DebugElement;
    let element: HTMLElement;

    beforeEach(async(() => {
        mockParams = Observable.of<Params>({foo: '3'});
        mockActivatedRoute = {params: mockParams};

        TestBed.configureTestingModule({
            declarations: [
                MyComponent
            ],
            providers: [
                {provide: ActivatedRoute, useValue: mockActivatedRoute}
            ]
        }).compileComponents();
    }));

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

        debugElement = fixture.debugElement;
        element = debugElement.nativeElement;

        fixture.detectChanges();
    });

    it('should set foo to "3"', () => {
        expect(component.foo).toBe('3');
    });
});

我的问题是我不知道如何等待，直到路由解析完成，我可以做一个 expect()。在此示例中，测试失败并显示 "Expected undefined to be '3'.".

有人可以帮我吗？！

谢谢！

Answer 1

好的，稍微阅读了angular2测试文档，我看到了他们的ActivatedRouteStub class。我创建了这个存根 class，并用这个新的 class 替换了我原来的模拟。现在它正在工作（识别第二个 beforeEach 中的 mockActivatedRoute.testParams = {foo: '3'}; 行）。

import {TestBed, ComponentFixture, async} from '@angular/core/testing';
import {DebugElement} from '@angular/core';
import {By} from '@angular/platform-browser';
import {Params, ActivatedRoute} from '@angular/router';

import {Observable} from 'rxjs';

import {MyComponent} from './MyComponent';

import { BehaviorSubject } from 'rxjs/BehaviorSubject';

@Injectable()
export class ActivatedRouteStub
{
    private subject = new BehaviorSubject(this.testParams);
    params = this.subject.asObservable();

    private _testParams: {};
    get testParams() { return this._testParams; }
    set testParams(params: {}) {
        this._testParams = params;
        this.subject.next(params);
    }
}

describe('MyComponent', () => {
    let mockParams, mockActivatedRoute;

    let component: MyComponent;
    let fixture: ComponentFixture<MyComponent>;
    let debugElement: DebugElement;
    let element: HTMLElement;

    beforeEach(async(() => {
        mockActivatedRoute = new ActivatedRouteStub();

        TestBed.configureTestingModule({
            declarations: [
                MyComponent
            ],
            providers: [
                {provide: ActivatedRoute, useValue: mockActivatedRoute}
            ]
        }).compileComponents();
    }));

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

        debugElement = fixture.debugElement;
        element = debugElement.nativeElement;

        mockActivatedRoute.testParams = {foo: '3'};

        fixture.detectChanges();
    });

    it('should set foo to "3"', () => {
        expect(component.foo).toBe('3');
    });
});

你觉得这样对吗？

测试依赖于路由参数的组件

Testing a component, which depends on a route param

angular

typescript

jasmine

angular2-routing

angular2-testing