webpack 打包优化

1. 利用缓存插件提升二次构建速度
   yarn add hard-source-webpack-plugin

const HardSourceWebpackPlugin = require('hard-source-webpack-plugin')

第一次构建耗时

第二次构建耗时

2. 图片压缩
yarn add image-webpack-loader

module.exports = {
  chainWebpack: config => {
    config.module
      .rule('images')
      .use('image-webpack-loader')
      .loader('image-webpack-loader')
      .options({
         bypassOnDebug: true
       })
      .end()
  }
}

压缩前

压缩后

3. 生成gzip文件
   yarn add compression-webpack-plugin

configureWebpack: {
    plugins: [
      // 大于10240byte文件会生成gzip文件
      new CompressionPlugin({
        test: /\.js$|\.html$|\.css/,
        threshold: 102400,
        deleteOriginalAssets: false
      })
    ]
  },

nginx需配置

http {
	...
    #开启gzip压缩
    gzip_static on;
}

4. 依赖包单独打包

chainWebpack: config => {
	config.optimization.splitChunks({
      chunks: 'all',
      maxInitialRequests: Infinity,
      minSize: 300000, // 依赖包超过300000bit将被单独打包
      automaticNameDelimiter: '-',
      cacheGroups: {
        vendor: {
          test: /[\\/]node_modules[\\/]/,
          name (module) {
            const packageName = module.context.match(/[\\/]node_modules[\\/](.*?)([\\/]|$)/)[1]
            return `chunk.${packageName.replace('@', '')}`
          },
          priority: 10
        }
      }
    })
 }

5. 使用TreeShaking擦除未使用的css

const PurgeCSSPlugin = require('purgecss-webpack-plugi')
const glob = require('glob');
const PATH = {
  src: path.resolve(__dirname, 'src')
}
module.exports = {
	configureWebpack: {
	    plugins: [
	      // 大于10240byte文件会生成gzip文件
	      new CompressionPlugin({
	        test: /\.js$|\.html$|\.css/,
	        threshold: 102400,
	        deleteOriginalAssets: false
	      }),
	      // new BundleAnalyzerPlugin()
	      new HardSourceWebpackPlugin(),
	      new PurgeCSSPlugin({
	        paths: glob.sync(`${PATH.src}/**/*`, { nodir: true }),
	      })
	    ]
	  },
}