Parcel Example - index.js

index.js

import * as React from "react";
import * as ReactDOM from "react-dom";

class App extends React.Component {
  render() {
    return (
      <div>
        <h1>Hello, World.</h1>
      </div>
    );
  }
}

const mountApp = document.getElementById("app");
ReactDOM.render(<App />, mountApp);