Angular 2 最终版本路由器单元测试

如何使用 karma 和 jasmine 对 Angular 2.0.0 版中的路由器进行单元测试？

这是我的旧单元测试在版本 2.0.0-beta.14 中的样子

import {
  it,
  inject,
  injectAsync,
  beforeEach,
  beforeEachProviders,
  TestComponentBuilder
} from 'angular2/testing';

import { RootRouter } from 'angular2/src/router/router';
import { Location, RouteParams, Router, RouteRegistry, ROUTER_PRIMARY_COMPONENT } from 'angular2/router';
import { SpyLocation } from 'angular2/src/mock/location_mock';
import { provide } from 'angular2/core';

import { App } from './app';

describe('Router', () => {

  let location, router;

  beforeEachProviders(() => [
    RouteRegistry,
    provide(Location, {useClass: SpyLocation}),
    provide(Router, {useClass: RootRouter}),
    provide(ROUTER_PRIMARY_COMPONENT, {useValue: App})
  ]);

  beforeEach(inject([Router, Location], (_router, _location) => {
    router = _router;
    location = _location;
  }));

  it('Should be able to navigate to Home', done => {
    router.navigate(['Home']).then(() => {
      expect(location.path()).toBe('');
      done();
    }).catch(e => done.fail(e));
  });

});

为了测试，我们现在使用创建一个测试模块TestBed https://angular.io/docs/ts/latest/api/core/testing/index/TestBed-class.html。我们可以使用TestBed#configureTestingModule并将元数据对象传递给它，就像我们传递给@NgModule

beforeEach(() => {
  TestBed.configureTestingModule({
    imports: [ /* modules to import */ ],
    providers: [ /* add providers */ ],
    declarations: [ /* components, directives, and pipes */ ]
  });
});

对于路由，而不是使用普通的RouterModule，我们会改为使用RouterTestingModule https://angular.io/docs/ts/latest/api/router/testing/index/RouterTestingModule-class.html。这设置了Router and Location，所以你不需要自己。您还可以通过调用将路由传递给它RouterTestingModule.withRoutes(Routes)

TestBed.configureTestingModule({
  imports: [
    RouterTestingModule.withRoutes([
      { path: 'home', component: DummyComponent }
    ])
  ]
})

为了得到Location and Router在测试中，同样的事情起作用，就像你的例子一样。

let router, location;

beforeEach(() => {
  TestBed...
});

beforeEach(inject([Router, Location], (_router: Router, _location: Location) => {
  router = _router;
  location = _location;
}));

您还可以根据需要注入每个测试

it('should go home',
    async(inject([Router, Location], (router: Router, location: Location) => {
})));

The async上面的用法就像done除非我们不需要显式调用done。在所有异步任务完成后，Angular 实际上会为我们做这件事。

获取提供者的另一种方法是从测试台获得。

let location, router;

beforeEach(() => {
  TestBed.configureTestingModule({
    imports: [RouterTestingModule.withRoutes([
      { path: 'home', component: DummyComponent }
    ])],
  });
  let injector = getTestBed();
  location = injector.get(Location);
  router = injector.get(Router);
});

这是一个完整的测试，重构您的示例

import { Component } from '@angular/core';
import { Location } from '@angular/common';
import { Router } from '@angular/router';
import { RouterTestingModule } from '@angular/router/testing';
import { fakeAsync, async, inject, TestBed, getTestBed } from '@angular/core/testing';
import { By } from '@angular/platform-browser';

@Component({
  template: `
    <router-outlet></router-outlet>
  `
})
class RoutingComponent { }

@Component({
  template: ''
})
class DummyComponent { }

describe('component: RoutingComponent', () => {
  let location, router;

  beforeEach(() => {
    TestBed.configureTestingModule({
      imports: [RouterTestingModule.withRoutes([
        { path: 'home', component: DummyComponent }
      ])],
      declarations: [RoutingComponent, DummyComponent]
    });
  });

  beforeEach(inject([Router, Location], (_router: Router, _location: Location) => {
    location = _location;
    router = _router;
  }));

  it('should go home', async(() => {
    let fixture = TestBed.createComponent(RoutingComponent);
    fixture.detectChanges();
    router.navigate(['/home']).then(() => {
      expect(location.path()).toBe('/home');
      console.log('after expect');
    });
  }));
});

UPDATE

另外，如果您想简单地模拟路由器（这实际上可能是进行单元测试的更好方法），您可以简单地执行以下操作

let routerStub;

beforeEach(() => {
  routerStub = {
    navigate: jasmine.createSpy('navigate'),
  };
  TestBed.configureTestingModule({
    providers: [ { provide: Router, useValue: routerStub } ],
  });
});

在测试中，您要做的就是测试当组件与存根交互时，是否使用正确的参数调用存根

expect(routerStub.navigate).toHaveBeenCalledWith(['/route']);

除非您确实想测试某些路由，否则这可能是首选方法。无需设置任何路由。在单元测试中，如果您使用真实的路由，则会涉及不必要的副作用，这些副作用可能会影响您真正尝试测试的内容，这只是组件的行为。组件的行为就是简单地调用navigate方法。不需要测试路由器是否工作。 Angular 已经保证了这一点。