webpack.config.js

const path = require('path');

const config = {
  context: __dirname,
  entry: './js/App.jsx',
  devtool: 'cheap-eval-source-map',
  output: {
    path: path.join(__dirname, 'public'),
    filename: 'bundle.js'
  },
  devServer: {
    publicPath: '/public/'
  },
  resolve: {
    extensions: ['.js', '.jsx', '.json']
  },
  stats: {
    colors: true,
    reasons: true,
    chunks: true
  },
  module: {
    rules: [
      {
        enforce: 'pre',
        test: /\.jsx?$/,
        loader: 'eslint-loader',
        exclude: /node_modules/
      },
      {
        test: /\.jsx?$/,
        loader: 'babel-loader',
        query: {
          presets: ['react', 'stage-0']
        }
      },
      {
        test: /\.css?$/,
        use: ['style-loader', 'css-loader']
      }
    ]
  }
};

if (process.env.NODE_ENV === 'production') {
  config.entry = './js/App.jsx';
  config.devtool = false;
  config.plugins = [];
}

module.exports = config;