unit-testing - 在 Angular 2 的构造函数中注入(inject)路由器的问题单元测试服务

Question

我正在尝试测试在其构造函数中注入(inject)了应用程序路由器的服务。按照 Julie Ralph 在 AngularConnect conf 2015 中提出的建议(以及她的存储库:https://github.com/juliemr/ng2-test-seed)， 我正在使用 Karma 和 Jasmine。

它遵循要测试的示例服务:

import { Router } from 'angular2/router';

export class ExampleService {
  constructor(router : Router) {
    this._router = router;
  }

  //...
}

现在，我只是在断言事实。它遵循服务测试:

import { it, describe, expect, inject, beforeEachProviders, MockApplicationRef } from 'angular2/testing';
import { ROUTER_PROVIDERS } from 'angular2/router';
import { provide, ApplicationRef } from 'angular2/core';

import { ExampleService } from 'example-service.js';

describe('ExampleService', () => {
  beforeEachProviders(() => [
    ROUTER_PROVIDERS, ExampleService,
    provide(ApplicationRef, { useClass: MockApplicationRef })
  ]);

  it('should validate the truth', inject([ExampleService], (exService) => {
    expect(true).toBeTruthy();
  }));
});

当我运行测试时 ( > karma start karma.config.js )，我得到一个 TypeError: Cannot read property 'length' of null

查看 router.js 源代码，看起来我应该在注入(inject)路由器之前引导至少一个组件。有没有 在测试中注入(inject) Router 依赖项的简单方法？

堆栈跟踪:

ORIGINAL EXCEPTION: TypeError: Cannot read property 'length' of null ORIGINAL STACKTRACE: TypeError: Cannot read property 'length' of null at routerPrimaryComponentFactory (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/router.js:2963:27) at Injector._instantiate (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11920:19) at Injector._instantiateProvider (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11859:21) at Injector._new (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11849:19) at InjectorDynamicStrategy.getObjByKeyId (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11733:42) at Injector._getByKeyDefault (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:12048:33) at Injector._getByKey (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:12002:21) at Injector._getByDependency (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11990:21) at Injector._instantiate (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11887:32) at Injector._instantiateProvider (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11859:21) at Injector._new (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11849:19) at InjectorDynamicStrategy.getObjByKeyId (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11733:42) at Injector._getByKeyDefault (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:12048:33) at Injector._getByKey (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:12002:21) at Injector._getByDependency (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11990:21) at Injector._instantiate (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11887:32) at Injector._instantiateProvider (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11859:21) at Injector._new (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11849:19) at InjectorDynamicStrategy.getObjByKeyId (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11733:42) at Injector._getByKeyDefault (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:12048:33) at Injector._getByKey (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:12002:21) at Injector._getByDependency (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11990:21) at Injector._instantiate (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11887:32) at Injector._instantiateProvider (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11859:21) at Injector._new (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11849:19) at InjectorDynamicStrategy.getObjByKeyId (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11733:42) at Injector._getByKeyDefault (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:12048:33) at Injector._getByKey (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:12002:21) at Injector.get (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11804:19) at C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/testing.dev.js:2477:25 at Array.map (native) at Array.map (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/es6-shim/es6-shim.js:1113:14) at FunctionWithParamTokens.execute (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/testing.dev.js:2476:33) at C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/testing.dev.js:2601:25 at Zone.run (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2-polyfills.js:138:17) at Zone.run (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/testing.dev.js:2544:30) at runInTestZone (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/testing.dev.js:2588:23) at Object. (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/testing.dev.js:2600:33) at attemptAsync (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:1819:24) at QueueRunner.run (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:1774:9) at QueueRunner.execute (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:1762:10) at Spec.Env.queueRunnerFactory (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:627:35) at Spec.execute (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:353:10) at Object.fn (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:2360:37) at attemptAsync (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:1819:24) at QueueRunner.run (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:1774:9) at QueueRunner.execute (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:1762:10) at Env.queueRunnerFactory (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:627:35) at Object.fn (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:2345:13) at attemptAsync (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:1819:24) at QueueRunner.run (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:1774:9) at C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:1801:16 at C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:1745:9 at queueRunnerFactory.onComplete (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:2348:17) at QueueRunner.clearStack (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:605:9) at QueueRunner.run (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:1784:12) at C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:1801:16 at C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:1745:9 at complete (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:365:9)

另见 https://github.com/angular/angular/issues/6325

Answer 1

问题解决，只需要提供ROUTER_PRIMARY_COMPONENT即可。

import {ROUTER_PRIMARY_COMPONENT} from 'angular2/router';

class MockPrimaryComponent {
}

beforeEachProviders(() => [
  ROUTER_PROVIDERS,
  provide(ROUTER_PRIMARY_COMPONENT, {useClass: MockPrimaryComponent}),
  ExampleService,
  provide(ApplicationRef, { useClass: MockApplicationRef })
]);