webpack-config-ex.js

export default {
  entry: .....,
  output: ....,
  plugins:[
    new webpack.ResolverPlugin(
      new webpack.ResolverPlugin.DirectoryDescriptionFilePlugin(
        'bower.json', ['main']
      )
  ],
  resolve: {
    //all these extensions will be resolved without specifying extension in the `require` function
    extensions: ['', '.js'],
    //files in these directory can be required without a relative path
    modulesDirectories: [
      'node_modules',
      'bower_components'
    ]
  }
};