happypack 提升 Webpack 构建速度

Happypack 的作用就是将文件解析任务分解成多个子进程并发执行，发挥多核 CPU 电脑的威力。子进程处理完任务后再将结果发送给主进程。所以可以大大提升 Webpack 的项目构件速度*
待实践
webpack.config.js

npm install happypack -D

const HappyPack = require('happypack');
const os = require('os');
const happyThreadPool = HappyPack.ThreadPool({ size: os.cpus().length });

module.exports = {
  module: {
    rules: [
      {
        test: /\.js$/,
        //把对.js 的文件处理交给id为happyBabel 的HappyPack 的实例执行
        loader: 'happypack/loader?id=happyBabel',
        //排除node_modules 目录下的文件
        exclude: /node_modules/
      },
      {
            test: /\.(css|less)$/,
            use: 'happypack/loader?id=styles'
      },
    ]
  },
plugins: [
    new HappyPack({
        //用id来标识 happypack处理那里类文件
      id: 'happyBabel',
      //如何处理  用法和loader 的配置一样
      loaders: [{
        loader: 'babel-loader?cacheDirectory=true',
      }],
      //共享进程池
      threadPool: happyThreadPool,
      //允许 HappyPack 输出日志
      verbose: true,
    }),
    new HappyPack({
        id: 'styles',
        loaders: [ 'style-loader', 'css-loader', 'less-loader' ]，
        //共享进程池
        threadPool: happyThreadPool,
    });
  ]
}