桶进口似乎破坏了装载顺序

Question

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

TypeError: Cannot read property 'toString' of undefined

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) => {
            expect(component).toBeTruthy();
        })
    );

}

进口似乎是个问题，因为我试图使用桶：

|
|- my-component
|  |- index.ts
|  |- my.component.ts
|  |- my.component.spec.ts
|
|- my-service
|  |- index.ts
|  |- my.service.ts
|
|- index.ts

在index.ts文件中，我正在执行以下操作：

export * from '<filename>';
export * from '<directory>';

import {MyService} from '../my-service/my.service';

...
const barrels: string[] = [
  ...,

  // App specific barrels.
  'app',
  'app/my-service',
  'app/my-component'
  /** @cli-barrel */
];

const cliSystemConfigPackages: any = {};
barrels.forEach((barrelName: string) => {
  cliSystemConfigPackages[barrelName] = { main: 'index' };
});

/** Type declaration for ambient System. */
declare var System: any;

// Apply the CLI SystemJS configuration.
System.config({
  map: {
    '@angular': 'vendor/@angular',
    'rxjs': 'vendor/rxjs',
    'main': 'main.js'
  },
  packages: cliSystemConfigPackages
});
...

Answer 1

我得看看你进口的桶里的东西才能确定，但听起来你需要改变你桶里出口的顺序。

angular2回购中的一个问题存在于以下位置:https://github.com/Angular/Angular/issues/9334

如果组件(a)从包含a和B的出口的桶中导入并使用服务/组件(B)，并且桶中的a出现在B之前，则B的导入值是未定义的。

export * from my-service;
export * from my-component;