webpack.config.js

module.exports = {
  // Your lib main file.
  entry: './src/index.js',

  // Where your lib will be used.
  // Can be "web", "webworker", "node",
  // "async-node", "node-webkit", "electron"
  // If you use webpack everywhere you'll
  // be fine with "node" most of the time
  target: 'node',
  
  resolve: {
    extensions: ['', '.js']
  },

  output: {
    path: './dist',
    filename: 'index.js',
    
    // The global name of your lib
    library: 'MyLib',
    libraryTarget: 'umd'
  },

  module: {
    loaders: [
      {
        // Just normal babel loader
        // config with es6 preset
        test: /\.js$/,
        loader: 'babel-loader',
        query: {
          presets: ['es2015']
        },
        exclude: /node_modules/
      }
    ]
  }
}