webpack.config.js

const webpack = require('webpack');
const UglifyJsPlugin = webpack.optimize.UglifyJsPlugin;
const path = require('path');
const env = require('yargs').argv.env; // use --env with webpack 2

let libraryName = 'ReactHeatmap';

let plugins = [], outputFile;

if (env === 'build') {
  plugins.push(new UglifyJsPlugin({ minimize: true }));
  outputFile = libraryName + '.min.js';
} else {
  outputFile = libraryName + '.js';
}

module.exports = {
  entry: __dirname + '/src/index.jsx',
  devtool: 'source-map',
  output: {
    path: __dirname + '/lib',
    filename: outputFile,
    library: libraryName,
    libraryTarget: 'umd',
    umdNamedDefine: true
  },
  externals: {
    react: 'react',
    'react-dom': 'react-dom',
    'heatmap.js': 'heatmap.js'
  },
  module: {
    rules: [
      {
        test: /\.jsx|.js$/,
        exclude: /(node_modules|bower_components)/,
        use: {
          loader: 'babel-loader'
        }
      },
      {
        test: /(\.jsx|\.js)$/,
        loader: "eslint-loader",
        exclude: /node_modules/
      }
    ]
  },
  resolve: {
    modules: [path.resolve('./src')],
    extensions: ['.json', '.js']
  },
  plugins: plugins
};