getInitialprops4.js

const PageWrapper = Comp =>
  class extends React.Component {
    static async getInitialProps(args) {
      return {
        ua: args.req ? args.req.headers['user-agent'] : navigator.userAgent,
        ...(Comp.getInitialProps ? await Comp.getInitialProps(args) : null),
      }
    }

    render() {
      const {ua, ...props} = this.props
      return (
        <UserAgentProvider ua={ua}>
          <Comp {...props} />
        </UserAgentProvider>
      )
    }
  }