webpack.config.build.js

const path = require('path');
const webpack = require('webpack');

module.exports = {
  entry: [
    './src/components/RadioButtonGroup'
  ],
  output: {
    path: path.join(__dirname, 'lib'),
    filename: 'index.js',
    libraryTarget: 'umd'
  },
  plugins: [
    new webpack.DefinePlugin({
      'process.env.NODE_ENV': JSON.stringify('development')
    })
  ],
  resolve: {
    modulesDirectories: ['node_modules', 'index'],
    extensions: ['', '.js', '.jsx']
  },
  module: {
    loaders: [
      {
        test: /\.js?/,
        exclude: /build|node_modules|styles/,
        loaders: ['babel'],
        include: path.join(__dirname, 'src')
      },
      {
        test: /\.css$/,
        loader: 'style!css'
      }
    ]
  },
  externals: [
    {
      react: {
        root: 'React',
        commonjs2: 'react',
        commonjs: 'react',
        amd: 'react'
      }
    }
  ]
};