babel.client.js

require('babel-register');
module.exports = require('./webpack.client');

isDev.js

module.exports = (process.env.BABEL_ENV && process.env.BABEL_ENV === 'development') ? true: false;

status-webpack-plugin.js

function StatusWebpackPlugin(options) {}

StatusWebpackPlugin.prototype.apply = function(compiler) {
  compiler.plugin("compile", function() {
      setTimeout(function(){
        console.log("webpack is compiling, dude...");
      },0);
  });
  compiler.plugin("emit", function(compilation, callback) {
    console.log("webpack is going to emit files...");
    callback();
  });
  compiler.plugin("done", function() {
      setTimeout(function(){
        console.log("webpack say it good, fire up...\n");
      },0);
  });
}

export default StatusWebpackPlugin;

uglifyjs.json

{
  "compress": {
    "warnings": false,
    "screw_ie8": true,
    "sequences": true,
    "dead_code": true,
    "drop_debugger": true,
    "comparisons": true,
    "conditionals": true,
    "evaluate": true,
    "booleans": true,
    "loops": true,
    "unused": true,
    "hoist_funs": true,
    "if_return": true,
    "join_vars": true,
    "cascade": true,
    "drop_console": true
  },
  "output": {
    "comments": false
  }
}

webpack.client.js

import IS_DEV from '../src/server/utils/isDev';
import path from 'path';
import webpack from 'webpack';
import ExtractTextPlugin from 'extract-text-webpack-plugin';
import CleanWebpackPlugin from 'clean-webpack-plugin';
import AssetsPlugin from 'assets-webpack-plugin';
import WebpackSHAHash from 'webpack-sha-hash';
import CaseSensitivePathsPlugin from 'case-sensitive-paths-webpack-plugin';
import StatusPlugin from './status-webpack-plugin';

const hash = IS_DEV ? '[name]' : '[name]-[chunkhash]';
const root = process.cwd();
const styleLoaders = ['css?minimize&sourceMap&importLoaders=5', 'postcss', 'sass?sourceMap'];
const prefetches = ['react', 'redux', 'd3', 'moment', 'classnames'];

var plugins = [
    new webpack.SourceMapDevToolPlugin('[file].map', "\n//# sourceMappingURL=/summary/static/[url]"),
    new AssetsPlugin({ filename: 'asset-manifest.json', path: path.join(root, '/build/static') }),
    new CaseSensitivePathsPlugin(),
    new CleanWebpackPlugin([path.join(root, '/build/static')], {'verbose': false}),
    new webpack.optimize.CommonsChunkPlugin('vendor', hash + '.js', (module) => {
        return module.resource && module.resource.indexOf(path.join(root, 'node_modules')) === 0;
    }),
    new webpack.optimize.CommonsChunkPlugin({ names: ["vendor", "manifest"] }),
    new webpack.DefinePlugin({
      'IS_BROWSER': true,
      'IS_DEV': IS_DEV,
      'process.env.NODE_ENV': JSON.stringify(IS_DEV ? 'development' : 'production')
    }),
    ...prefetches.map((i) => new webpack.PrefetchPlugin(i)),
    ...(IS_DEV ? [
            new webpack.HotModuleReplacementPlugin(),
            new StatusPlugin()
        ] : [
            new webpack.optimize.MinChunkSizePlugin({ minChunkSize: 40000 }),
            new webpack.ContextReplacementPlugin(/.*$/, /NEVER_MATCH^/), // ignore dynamic reqires
            new webpack.optimize.DedupePlugin(),
            new webpack.optimize.OccurenceOrderPlugin(),
            new WebpackSHAHash(),
            new webpack.optimize.AggressiveMergingPlugin(),
            new ExtractTextPlugin(hash + '.css'),
            new webpack.optimize.UglifyJsPlugin(require('./uglifyjs.json'))
        ]
    )
];

module.exports = {
    context: path.join(root, 'src'),
    entry: {
        main: IS_DEV ? ['./client/js/index.js', 'webpack-hot-middleware/client', './client/scss/index.scss'] : ['./client/js/index.js', './client/scss/index.scss'],
        prerender: ['./client/scss/prerender.scss'],
        serviceworker: ['./client/js/utils/serviceworker.js']
    },
    output: {
        path: path.join(root, '/build/static'),
        publicPath: IS_DEV ? `http://localhost:8080/summary/static/` : '/summary/static/', // needed so fonts can be found
        filename: hash + '.js',
        chunkFilename: hash + '.js'
    },
    plugins: plugins,
    module: {
      loaders: [{
          test: /\.js$/,
          loader: 'babel',
          include: path.join(root, 'src'),
            query: {
              cacheDirectory: IS_DEV,
              babelrc: false,
              presets: [
                  'react',
                  'es2015',
                  ...(IS_DEV) ? ['react-hmre'] : []
              ],
              plugins: [
                'transform-object-assign',
                'transform-object-rest-spread',
                ...(IS_DEV) ? [] : [
                  'transform-react-remove-prop-types',
                  'transform-react-constant-elements',
                  'transform-react-inline-elements',
                ]
              ]
            },
          },
          {
              test: /\.json$/, loader: 'json'
          },
          {
              test: /\.(jpe?g|png|gif)([\?]?.*)$/,
              include: [path.join(root, 'src/client')],
              loaders: [
                  'url?limit=100&digest=hex',
                  'image-webpack?bypassOnDebug&optimizationLevel=7&interlaced=false'
              ]
          },
          {
             test: /\.(woff|woff2|eot|ttf|svg)([\?]?.*)$/,
             loader: 'file?name=[name].[ext]' //name fonts to enable dedupe shared header/footer fonts
         },
          {
              test: /.s?css$/,
              include: [path.join(root, 'src/client'), path.resolve(root, 'node_modules')],
              loader: IS_DEV ? 'style!' + styleLoaders.join('!') : ExtractTextPlugin.extract('style', styleLoaders)
          }
      ]
  },
  postcss: function () {
      return [
        require('autoprefixer')({ browsers: ['last 2 versions'] })
      ];
  }
};