server.js

// Note: this setup is described in @jlongster's "Backend with Webpack" post
// https://github.com/jlongster/backend-with-webpack/

var webpack = require('webpack');
var path = require('path');
var fs = require('fs');
var nodemon = require('nodemon');
var WebpackDevServer = require('webpack-dev-server');

var nodeModules = {};
fs.readdirSync('node_modules')
  .filter(function(x) {
    return ['.bin'].indexOf(x) === -1;
  })
  .forEach(function(mod) {
    nodeModules[mod] = 'commonjs ' + mod;
  });

var backendConfig = {
  entry: './src/index.js',
  devtool: 'source-map',
  debug: true,
  target: 'node',
  output: {
    path: path.join(__dirname, 'build'),
    filename: 'backend.js'
  },
  node: {
    __dirname: true,
    __filename: true
  },
  module: {
    loaders: [{
      test: /\.js$/,
      include: path.join(__dirname, 'src'),
      loaders: ['babel']
    }]
  },
  externals: nodeModules,
  recordsPath: path.join(__dirname, 'build', '_records'),
  plugins: [
    new webpack.IgnorePlugin(/\.(css|less)$/),
    new webpack.BannerPlugin('require("source-map-support").install();',
                             { raw: true, entryOnly: false }),
    new webpack.HotModuleReplacementPlugin({ quiet: true })
  ]
};

var running = false;
webpack(backendConfig).watch(100, function(err, stats) {
  if (!running) {
    running = true;
    nodemon({
      execMap: {
        js: 'node'
      },
      script: path.join(__dirname, 'build', 'backend'),
      ignore: ['*'],
      watch: ['foo/'],
      ext: 'noop'
    });
  }

  // There's a trick here. Restart will just send SIGUSR2 to our process.
  // src/signal.js will intercept it and handle hot update instead of restarting.

  nodemon.restart();
});