var path = require('path');

module.exports = {
  entry:  './resources/js/app.js',
  output: {
    path: path.resolve(__dirname, 'public/dist/'),
    filename: 'app.js'
  },
  module: {
    rules: [
      {
        test: /\.js$/,
        exclude: /node_modules/,
        use: {
          loader: 'babel-loader',
          options: {
            presets: ['@babel/preset-react']
          }
        }
      }
    ]
  }
}

import React from 'react';
import ReactDOM from 'react-dom';

function Example() {
    return (
        <h1>I'm an example component!</h1>
    );
}

export default Example;

if (document.getElementById('component-example')) {
    ReactDOM.render(<Example />, document.getElementById('component-example'));
}

require('./components/Example');

  <div id="component-example"></div>
  <script src="dist/app.js"></script>