text: /**
   * render
   * ReactDOM.render(element, container)
   */
  
  function render(element, container) {
    const dom = element.type == "TEXT_ELEMENT"
      ? document.createTextNode("")
      : document.createElement(element.type);
  
    // 添加属性
    const isProperty = key => key !== "children"
    Object.keys(element.props)
      .filter(isProperty)
      .forEach(name => {
        dom[name] = element.props[name]
      })
  
    // 子级节点render
    element.props.children.forEach(child =>
      render(child, dom)
    );
  ​
    container.appendChild(dom);
  }
  