webpack.config.js

const path = require('path');
const webpack = require('webpack');
module.exports = {
  entry: './src/index.js',
  output: {
    path: path.resolve(__dirname, 'lib'),
    filename: 'index.js',
    library: 'reactDeviceBattery',
    libraryTarget: 'umd'
  },
  devtool: "source-map",
  module: {
    rules: [
      {
        test: /\.js$/,
        include: path.resolve(__dirname, 'src'),
        exclude: /(node_modules|bower_components|lib)/,
        loader: 'babel-loader'
      }
    ]
  },
  externals: {
    'react': {
      root: 'React',
      commonjs2: 'react',
      commonjs: 'react',
      amd: 'react'
    }
  },
  plugins: [
    new webpack.optimize.UglifyJsPlugin({
      sourceMap: true,   // enable source maps to map errors (stack traces) to modules
      output: {
        comments: false, // remove all comments
      },
    }),
    new webpack.DefinePlugin({
        "process.env": {
          NODE_ENV: JSON.stringify("production"),
        },
    }),
  ]
};