webpack.config.js

const path = require('path');

module.exports = {
  entry: './frontend/index.jsx',
  output: {
    path: path.resolve(__dirname, 'app','assets', 'javascripts'),
    filename: 'bundle.js'
  },
  module: {
    rules: [
      {
        test: [/\.jsx?$/],
        exclude: /(node_modules)/,
        use: {
          loader: 'babel-loader',
          query: {
            presets: ['env', 'react'],
            plugins: ["transform-class-properties"]
          }
        },
      }
    ]
  },
  devtool: 'source-map',
  resolve: {
    extensions: ['.js', '.jsx', '*']
  }
}