renderMidiDevice.js

import React from 'react';
import { MidiDevice } from 'hypothetical-react-midi';
import { render } from 'react-dom';

function App({ input, output }) {
  return (
    <MidiDevice input={input} output={output}>
      // ...
    </MidiDevice>
  );
}

findMidiDevices('Launchpad')
  .then(({ input, output }) => {
    render(
      <App input={input} output={output} />,
      document.querySelector('main')
    );
  });