old_contents: var path = require('path');
  var webpack = require('webpack');
  var merge = require('webpack-merge');
  var HtmlWebpackPlugin = require('html-webpack-plugin');
  var WebpackCleanupPlugin = require('webpack-cleanup-plugin');
  
  var webpackBase = require('./webpack.base.js');
  
  module.exports = merge(webpackBase, {
    plugins: [
      new webpack.DefinePlugin({
        'process.env.NODE_ENV': '"production"'
      }),
  
      new HtmlWebpackPlugin({
        inject: 'body',
        template: path.resolve(__dirname, '../src/index.html'),
        minify: {
          caseSensitive: true,
          collapseWhitespace: true
        },
        favicon: path.resolve(__dirname, '../src/assets/images/favicon.ico')
      }),
      new WebpackCleanupPlugin(),
      new webpack.optimize.OccurenceOrderPlugin(),
      new webpack.optimize.UglifyJsPlugin({
        compressor: {
          warnings: false
        }
      }),
    ]
  });
  
new_contents: var path = require('path');
  var webpack = require('webpack');
  var merge = require('webpack-merge');
  var HtmlWebpackPlugin = require('html-webpack-plugin');
  var WebpackCleanupPlugin = require('webpack-cleanup-plugin');
  
  var webpackBase = require('./webpack.base.js');
  
  module.exports = merge(webpackBase, {
    plugins: [
      new webpack.DefinePlugin({
        'process.env': {
          NODE_ENV: '"production"'
        }
      }),
  
      new HtmlWebpackPlugin({
        inject: 'body',
        template: path.resolve(__dirname, '../src/index.html'),
        minify: {
          caseSensitive: true,
          collapseWhitespace: true
        },
        favicon: path.resolve(__dirname, '../src/assets/images/favicon.ico')
      }),
      new WebpackCleanupPlugin(),
      new webpack.optimize.OccurenceOrderPlugin(),
      new webpack.optimize.UglifyJsPlugin({
        compressor: {
          warnings: false
        }
      }),
    ]
  });
  
subject: Refactor process.env on webpack production