小编awi*_*man的帖子

我有一个要进行单元测试的组件，但我不断收到这些错误，具体取决于我的导入语句：

Error: Cannot resolve all parameters for 'MyComponent'(undefined, FormBuilder).

TypeError: Cannot read property 'toString' of undefined

我的组件需要 2 个参数，一个是 FormBuilder，一个是自定义服务，必须注入：

import {MyService} from '../';

@Component({
    ...,
    providers: [MyService]
})
class MyComponent {
    constructor(service: MyService, fb: FormBuilder) { ... }
    ...
}

我的单元测试设置如下：

import {MyComponent} from './';
import {MyService} from '../';

describe('Component: MyComponent', () => {

    let builder: TestComponentBuilder;

    beforeEachProviders(() => [
        MyService,
        MyComponent
    ]);

    beforeEach(inject([TestComponentBuilder], function (tcb: TestComponentBuilder) {
        builder = tcb;
    }));

    it('should inject the component', inject([MyComponent],      
        (component: MyComponent) …