Node.js Server with webpack and auto reload

dev-server.js

const { fork } = require('child_process');
const webpack = require('webpack');

const webpackServerConfig = require('./webpack.server.js');

let bundler = webpack(webpackServerConfig);
let child;

bundler.watch({}, (err, status) => {

  if (err) {
    console.error(err);
    return;
  }
  if (child && child.connected) {
    child.on('close', () => {
      console.log('Starting server...');
      child = fork('./build/backend.js');
    });
    console.log('Killing server...');
    child.kill('SIGHUP');
  } else {
    console.log('Starting server...');
    child = fork('./build/backend.js');
  }

});

webpack.server.js

const webpack = require('webpack');
const path = require('path');
const fs = require('fs');

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

module.exports = {
  entry: ['babel-polyfill', path.join(__dirname, 'server/index.js')],
  target: 'node',
  output: {
    path: path.join(__dirname, 'build'),
    filename: 'backend.js'
  },
  module: {
    loaders: [
      {
        test: /\.jsx?$/,
        include: [ path.join(__dirname, 'server') ],
        loader: 'babel'
      }
    ]
  },
  externals: nodeModules,
  plugins: [
    new webpack.BannerPlugin('require("source-map-support").install();',
                             { raw: true, entryOnly: false })
  ],
  devtool: 'source-map'
}