咨询：.js/.jsx文件中类型定义实现及对应VSCode扩展

我正在研读react-grid-layout库，对.js/.jsx文件中这种类型定义的实现方式感到困惑，示例代码如下：

type Props = {
  children: ReactElement<any>,
  cols: number,
  containerWidth: number,
  margin: [number, number],
  containerPadding: [number, number],
  rowHeight: number,
  maxRows: number,
  isDraggable: boolean,
  isResizable: boolean,
  isBounded: boolean,
  static?: boolean,
  useCSSTransforms?: boolean,
  usePercentages?: boolean,
  transformScale: number,
  droppingPosition?: DroppingPosition,

  className: string,
  style?: Object,
  // Draggability
  cancel: string,
  handle: string,

  x: number,
  y: number,
  w: number,
  h: number,

  minW: number,
  maxW: number,
  minH: number,
  maxH: number,
  i: string,

  resizeHandles?: ResizeHandleAxis[],
  resizeHandle?: ResizeHandle,

  onDrag?: GridItemCallback<GridDragEvent>,
  onDragStart?: GridItemCallback<GridDragEvent>,
  onDragStop?: GridItemCallback<GridDragEvent>,
  onResize?: GridItemCallback<GridResizeEvent>,
  onResizeStart?: GridItemCallback<GridResizeEvent>,
  onResizeStop?: GridItemCallback<GridResizeEvent>
};

这是Flow的类型标注语法，Flow是Facebook推出的静态类型检查工具，用来给JavaScript添加类型约束。

VSCode里支持这种写法的扩展是Flow Language Support，安装后它会自动识别.js/.jsx文件中的Flow类型语法，提供语法高亮、类型提示、实时错误检查等功能。使用前需要确保项目已配置Flow（比如项目根目录存在.flowconfig文件），也可以通过VSCode相关设置让扩展直接解析这类类型语法。

内容的提问来源于stack exchange，提问作者Andy95