const path = require('path');
const MiniCssExtractPlugin = require('mini-css-extract-plugin');//生产环境下抽离出css模块
const OptimizeCSSAssetsPlugin = require("optimize-css-assets-webpack-plugin");//生产环境下压缩css模块
const UglifyJsPlugin = require("uglifyjs-webpack-plugin");//生产环境下压缩js模块
const merge = require('webpack-merge');
const common = require('./webpack.common');
let prodConfig = {
  mode: 'production',
  output: {
    filename: "[name]-main.[hash].js",
    path: path.resolve(__dirname, 'dist')
  },
  module: {
    rules: [
      {
        test: /\.(sc|sa|c)ss$/, use: [ MiniCssExtractPlugin.loader//对抽离css模块的配置，此时将不再使用style-loader
          , {
            loader: 'css-loader',
            options: {sourceMap: true}
          }, {
            loader: 'sass-loader',
            options: {sourceMap: true}
          }]
      }

    ]
  },
  plugins: [
    new MiniCssExtractPlugin({
      filename: "[name].[hash].css",
      chunkFilename: "[id].[hash].css"
    })//对抽离css模块的配置
  ],
  optimization: {
    minimizer: [
      new UglifyJsPlugin({//压缩js文件，production下有用
        cache: true,
        parallel: true,
        sourceMap: true // set to true if you want JS source maps
      }),
      new OptimizeCSSAssetsPlugin({})//压缩css文件，production下有用
    ]
  }
};
module.exports = merge(common,prodConfig);