webpack.config.js

const webpack = require('webpack')

module.exports = {
  output: {
    library: 'History',
    libraryTarget: 'umd'
  },

  module: {
    loaders: [
      { test: /\.js$/, exclude: /node_modules/, loader: 'babel' }
    ]
  },

  plugins: [
    new webpack.DefinePlugin({
      'process.env.NODE_ENV': JSON.stringify(process.env.NODE_ENV || 'development')
    })
  ]
}