如何使用本机模块中的`ref`测试组件实例

Question

我对mock函数有疑问

class MyScreen extends Component {
  constructor(props) {
    this.video = React.createRef();
  }
render() {
return (
  <VideoPlayer
    ref={this.video}
    onVideoSuccess={() => {
      this.video.current.startVideo();
    }}
  />);
 }
}

我如何通过this.video.current.startVideo()测试通过，但我不知道如何模拟组件startVideo()的功能VideoPlayer

export default class VideoPlayer extends Component {
  startVideo() { ... }
  play() {...}
  pause() {...}
  stop() {...}
  render() {
    return <VideoPlayerView {...this.props} />
  }
}