Webpack web-workers loader not working

I'm building an app using webpack and I'm trying to add some web workers, I'm using a built-in plugin to load them, but I followed the example here, the official repository, and I couldn't make it work. My webpack.dev.js looks like this:

import webpack              from 'webpack';
import assign               from 'object-assign';
import webpackDevMiddleware from 'webpack-dev-middleware';
import webpackHotMiddleware from 'webpack-hot-middleware';

import prodCfg              from './webpack.prod.config.js';

var ExtractTextPlugin = require("extract-text-webpack-plugin");
var DEBUG = process.env.NODE_ENV !== 'production' ? true : false;
var styles = 'css!less';

Object.assign = assign;

export default function (app) {
  const config = Object.assign(prodCfg, {
    devtool: 'cheap-module-inline-source-map',
    entry:  
     [
      'webpack-hot-middleware/client',
      './client',
      'styles/main.less'
    ],
    module: {
      loaders: [
        {
          test:    /\.jsx?$/,
          exclude: /node_modules/,
          loader:  'babel',
          query:   {
            plugins: [
              [
                'react-transform', {
                transforms: [{
                  transform: 'react-transform-hmr',
                  imports:   ['react'],
                  locals:    ['module']
                }]
              }
              ]
            ]
          }
        },
        {
          test: /\.css$/,
          loader: DEBUG ? 'style!' + styles : ExtractTextPlugin.extract(styles)
        },
        { 
          test: /\.less$/, 
          loader: DEBUG ? 'style!' + styles : ExtractTextPlugin.extract(styles)
        }
      ]
    },
    plugins: [
      new webpack.optimize.OccurenceOrderPlugin(),
      new webpack.HotModuleReplacementPlugin(),
      new webpack.NoErrorsPlugin(),
      new ExtractTextPlugin("style.css", {allChunks: true })
    ],
    worker: {
      output: {
        filename: "hash.worker.js",
        chunkFilename: "[id].hash.worker.js"
      }
    }
  });

  const compiler = webpack(config);

  app.use(webpackDevMiddleware(compiler, {noInfo: true, publicPath: config.output.publicPath}));
  app.use(webpackHotMiddleware(compiler));
}

and when I try to load the file I try it like this:

var Worker = require("worker!worker.js");

It would never find the file, the only files exported by webpack are bundle.js and style.css, it looks like the worker loader is not loading anything at all, or maybe I just don't understand the logic behind the loader, anyway there isn't much documentation about this nor implemented examples. So I hope someone had implemented this successfully and can shed some light on my problem.

Any help would be very welcomed! Thank you very much in advance!