webpack.prod.js

const webpack = require('webpack');
const merge = require('webpack-merge');
const ExtractTextPlugin = require('extract-text-webpack-plugin');
const UglifyJSPlugin = require('uglifyjs-webpack-plugin');

const common = require('./webpack.common.js');

module.exports = merge(common, {
  module: {
    rules: [
      {
        test: /\.scss$/,
        use: ExtractTextPlugin.extract({
          fallback: 'style-loader',
          use: [{
            loader: 'css-loader',
            options: {
              modules: true,
              localIdentName: '[path]___[name]__[local]___[hash:base64:5]'
            }
          },
          {
            loader: 'sass-loader'
          }]
        })
      }
    ]
  },
  plugins: [
    new UglifyJSPlugin(),
    new ExtractTextPlugin('[name].[chunkhash].css'),
    new webpack.DefinePlugin({
      'process.env.NODE_ENV': JSON.stringify('production')
    })
  ]
});