Angular 2 组件测试错误：无法解析“TestComponentBuilder”的所有参数

Question

我正在尝试进行 Angular 2.0 组件测试。我使用this 帖子作为参考（Angular 2.0 dos 中还没有参考）。

这是我的测试：

import 'reflect-metadata';
import {
  it,
  describe,
  expect,
  inject,
  injectAsync,
  beforeEach,
  beforeEachProviders,
  TestComponentBuilder,
  ComponentFixture
} from 'angular2/testing';
import {Main} from './index';

describe('Main', () => {

  // provide our implementations or mocks to the dependency injector
  beforeEachProviders(() => [
    Main
  ]);

  it('should have title', inject([ Main ], (main) => {
    expect(main.title).toEqual('Hello Angular 2.0');
  }));

  it('should add item to list', injectAsync([TestComponentBuilder, Main], (tcb: TestComponentBuilder, main) => {
    return tcb.createAsync(Main).then((componentFixture: ComponentFixture) => {
      const element = componentFixture.nativeElement;
      expect(element.querySelectorAll('input').length).toBe(1);
    });
  }));
})

现在，我在运行这些测试时收到Cannot resolve all parameters for 'TestComponentBuilder' 错误。尝试将 TestComponentBuilder 添加到 beforeEachProviders 结果却出现不同的错误：

Cannot resolve all parameters for 'TestComponentBuilder'(?).

我做错了什么？

Answer 1

您需要以这种方式设置提供者进行测试：

(...)

import {setBaseTestProviders} from 'angular2/testing';

import {
  TEST_BROWSER_PLATFORM_PROVIDERS,
  TEST_BROWSER_APPLICATION_PROVIDERS
} from 'angular2/platform/testing/browser';

describe('Test suite', () => {
  setBaseTestProviders(TEST_BROWSER_PLATFORM_PROVIDERS,
                    TEST_BROWSER_APPLICATION_PROVIDERS);

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

  (...)
});

这是一个示例 plunkr：https://plnkr.co/edit/oVBPsH?p=preview。