title: webpack module not found
body: <p>I am using  webpack 1.13.1</p>
  
  <p>I get this error when I want to run webpack </p>
  
  <pre><code>Module not found: Error: Cannot resolve 'file' or 'directory' 
  /home/tetar/grails-reactjs-master/src/main/js
  resolve file
  /home/tetar/grails-reactjs-master/src/main/js/undefined doesn't exist
  /home/tetar/grails-reactjs-master/src/main/js/undefined.webpack-
  loader.js doesn't exist [...]
  [/home/tetar/grails-reactjs-master/src/main/js/undefined.js]
  @ ./src/main/js/test.js 3:0-21
  </code></pre>
  
  <p>In my test.js I only have 2 test line </p>
  
  <pre><code>require ('./test.css');
  module.exports = "test fail"
  </code></pre>
  
  <p>and there is my webpack config</p>
  
  <pre><code> var path = require('path');
   var root = path.resolve(__dirname);
   var ExtractTextPlugin = require("extract-text-webpack-plugin");
   var extractCSS = new ExtractTextPlugin('bundle.css');
  
  module.exports = {
  
   entry: {
      index: ['./src/main/js/index.js']
  },
  output: {
      path: path.resolve(__dirname, './grails-app/assets/javascripts'),
      publicPath: '/assets/',
      filename: 'bundle.js'
  },
  module: {
      loaders: [
          {
              test: /\.js$/,
              loader: 'babel',
              exclude: /node_modules/,
              include : root
          },
          {
              test: /\.css$/,
              loaders : extractCSS.extract(['css'])
          }
      ]
    }
  };
  </code></pre>
  
  <p>do you have any idea how to solve this problem ?</p>