server.js

// server/index.js
require('babel-register')

const universalHook = require('./universal-hook').default
const webpackDev = require('../../webpack/webpack.config.dev').default
const config = require('../../webpack/config').default

universalHook(webpackDev, config)

require('./server')

universalHook.js

import fs from 'fs'
import { interpolateName } from 'loader-utils'

const ext = [
  '3gp', 'a', 'ai', 'aif', 'aiff', 'asc', 'asf', 'asm', 'asx', 'atom', 'au',
  'avi', 'bat', 'bin', 'bmp', 'bz2', 'c', 'cab', 'cc', 'chm', 'class', 'com',
  'conf', 'cpp', 'crt', 'css', 'csv', 'cxx', 'deb', 'der', 'diff', 'djv', 'djvu',
  'dll', 'dmg', 'doc', 'dot', 'dtd', 'dvi', 'ear', 'eml', 'eps', 'exe', 'f',
  'f77', 'f90', 'flv', 'for', 'gem', 'gemspec', 'gif', 'gz', 'h', 'hh', 'htm',
  'html', 'ico', 'ics', 'ifb', 'iso', 'jar', 'java', 'jnlp', 'jpeg', 'jpg', 'js',
  'json', 'log', 'm3u', 'm4v', 'man', 'mathml', 'mbox', 'mdoc', 'me', 'mid',
  'midi', 'mime', 'mml', 'mng', 'mov', 'mp3', 'mp4', 'mp4v', 'mpeg', 'mpg', 'ms',
  'msi', 'odp', 'ods', 'odt', 'ogg', 'p', 'pas', 'pbm', 'pdf', 'pem', 'pgm',
  'pgp', 'pkg', 'pl', 'pm', 'png', 'pnm', 'ppm', 'pps', 'ppt', 'ps', 'psd', 'py',
  'qt', 'ra', 'rake', 'ram', 'rar', 'rb', 'rdf', 'roff', 'rpm', 'rss', 'rtf',
  'ru', 's', 'sgm', 'sgml', 'sh', 'sig', 'snd', 'so', 'svg', 'svgz', 'swf', 't',
  'tar', 'tbz', 'tcl', 'tex', 'texi', 'texinfo', 'text', 'tif', 'tiff', 'torrent',
  'tr', 'txt', 'vcf', 'vcs', 'vrml', 'war', 'wav', 'wma', 'wmv', 'wmx', 'wrl',
  'wsdl', 'xbm', 'xhtml', 'xls', 'xml', 'xpm', 'xsl', 'xslt', 'yaml', 'yml', 'zip'
]

function getLoaderExt(originRegexp, extList) {
  const extToString = extList.join(' ')
  const stripTestRegexp = originRegexp.source.replace(/(\\\.)|(\$)/g, '')
  const regexpMatchExt = new RegExp(`\\b${stripTestRegexp}\\b`, 'ig')

  return extToString.match(regexpMatchExt)
}

export default function universalHook(webpackConfig, params = {}) {
  if (process.env.NODE_ENV === 'production') return null

  const options = {
    stylesName: '[name]_[local]__[hash:base64:5]',
    ...params,
  }

  const loaders = webpackConfig.module.loaders
  const hooks = loaders.filter(loader => loader.hook)

  if (hooks.length === 0) return null

  hooks.forEach(loader => {
    if(loader.hook === 'file') {
      if (process.env.NODE_ENV !== 'production' && loader.loader !== 'file') {
        throw new Error(
          `In development mode include only one file-loader`
        )
      }
      const loaderExt = getLoaderExt(loader.test, ext)
      loaderExt.forEach(ext => {
        if (require.extensions[`.${ext}`]) return null

        require.extensions[`.${ext}`] = function (require, filename) {
          const content = fs.readFileSync(filename)
          const webpackName = interpolateName({resourcePath: filename}, '[hash].[ext]', {content});
          require.exports = webpackConfig.output.publicPath + webpackName
        }
      })
    }

    if(loader.hook === 'css') {
      const hook = require('css-modules-require-hook')
      hook({
        generateScopedName: options.stylesName,
      })
    }
  })
}

webpack.dev.config.js

  module: {
    loaders: [
      { test: /\.js$/,  loaders: ['babel'], include: config.src },
      { test: /\.css$/, loaders: ['style', `css?modules&localIdentName=${config.stylesName}`], hook: 'css'},
      { test: /\.(jpe?g|png|gif|svg)$/, loader: 'file', hook: 'file'},
    ],
  }