example webpack

webpack.config.js

const webpack = require('webpack')
var path = require('path')
var BundleAnalyzerPlugin = require('webpack-bundle-analyzer').BundleAnalyzerPlugin
module.exports = {
  devtool: 'cheap-source-map',
  entry: ['./index.js'],
  watchOptions: {
    ignored: /node_modules/
  },
  module: {
    rules: [
      {
        test: /(\.jsx|\.js)$/,
        exclude: /node_modules/,
        use: [{ loader: 'babel-loader' }]
      },
      {
        test: /(\.scss$|\.css$|\.sass$)/,
        use: [
          { loader: 'style-loader' },
          {
            loader: 'css-loader',
            options: {
              modules: true,
              localIdentName: '[path][name]__[local]--[hash:base64:5]'
            }
          },
          { loader: 'sass-loader' }
        ]
      }
    ]
  },
  resolve: {
    modules: ['node_modules', 'src'],
    extensions: ['.js', '.jsx'],
    alias: {
      Globals: path.resolve(__dirname, 'globals/')
    }
  },
  output: {
    path: __dirname + '/dist',
    publicPath: '/',
    filename: 'bundle.js',
    chunkFilename: '[name].bundle.js'
  },
  devServer: {
    contentBase: './dist',
    host: '0.0.0.0',
    watchOptions: {
      ignored: /node_modules/
    },
    noInfo: true,
    historyApiFallback: true
  },
    externals: {
    react: {
      root: 'React',
      commonjs2: 'react',
      commonjs: 'react',
      amd: 'react',
      umd: 'react'
    }
  },
  performance: {
    hints: false
  },
  plugins: [
    new BundleAnalyzerPlugin({
      analyzerMode: 'static'
    }),
    new webpack.DefinePlugin({
      'process.env': {
        NODE_ENV: JSON.stringify('production')
      }
    })
  ]
}