interface PropsType {
  children: JSX.Element
  name: string
}

class Component extends React.Component‹PropsType, {}› {
  render() {
    return (
      ‹h2›
        {this.props.children}
      ‹/h2›
    )
  }
}

// OK
‹Component›
  ‹h1›Hello World‹/h1›
‹/Component›

// Error: children is of type JSX.Element not array of JSX.Element
‹Component›
  ‹h1›Hello World‹/h1›
  ‹h2›Hello World‹/h2›
‹/Component›

// Error: children is of type JSX.Element not array of JSX.Element or string.
‹Component›
  ‹h1›Hello‹/h1›
  World
‹/Component›