Test.tsx

import * as React from 'react'

class Test extends React.Component<any, any> {
  constructor (props: any) {
    super(props)
  }
  render () {
    return <Register foo='This is '>my beloved child</Register>
  }
}
const Register: any = ({ foo, children }: any) => {
  return <div>{foo} + {children}</div>
}

export default Test