webpack.prod.js

const merge = require('webpack-merge')
const UglifyJSPlugin = require('uglifyjs-webpack-plugin')
const ExtractTextPlugin = require('extract-text-webpack-plugin')
const common = require('./webpack.common')

const extractSass = new ExtractTextPlugin({
  filename: '[name].[md5:contenthash:hex:20].css'
})

module.exports = merge(common, {
  devtool: 'source-map',
  module: {
    rules: [
      {
        test: /\.(scss|css)$/,
        use: extractSass.extract({
          use: [
            {
              loader: 'css-loader'
            },
            {
              loader: 'postcss-loader',
              options: {
                plugins: function() {
                  return [require('precss'), require('autoprefixer')]
                }
              }
            },
            {
              loader: 'sass-loader'
            }
          ]
        })
      }
    ]
  },
  plugins: [
    new UglifyJSPlugin({
      sourceMap: true
    }),
    extractSass
  ]
})