webpack.config.js

const webpack = require('webpack');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const CopyWebpackPlugin = require('copy-webpack-plugin')
const path = require('path');

module.exports = {
  entry: './src/index.js',
  module: {
    rules: [
      {
        test: /\.(js|jsx)$/,
        exclude: /node_modules/,
        use: ['babel-loader']
      }
    ]
  },
  resolve: {
    extensions: ['*', '.js', '.jsx']
  },
  output: {
    path: __dirname + '/build',
    publicPath: '/',
    filename: 'bundle.js'
  },
  plugins: [
    new webpack.HotModuleReplacementPlugin(),
    new HtmlWebpackPlugin({
      template: "./public/index.html"
    }),
    new CopyWebpackPlugin([
      { from: 'public/workers', to: 'workers' }
    ])
  ],
  devServer: {
    contentBase: path.join(__dirname, 'public'),
    hot: true
  }
};