webpack中的runtimeChunk

作用：打包时生成一个体积很小runtime.xxx.js文件，用作映射其他chunk文件，目的是更新后，以较小的代价利用缓存，提升页面加载速度。

结合script-ext-html-webpack-plugin插件可将runtime文件内联进html文件，减少请求

const path = require('path');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const { CleanWebpackPlugin } = require('clean-webpack-plugin');
const ScriptExtHtmlWebpackPlugin= require('script-ext-html-webpack-plugin')

module.exports = {
  mode: 'production',
  entry: {
    index: './src/index.js'
  },
  output: {
    filename: '[name].[contenthash].js',
    path: path.resolve(__dirname, 'dist'),
    publicPath: '/'
  },
  devtool: 'inline-source-map',
  plugins: [
    new HtmlWebpackPlugin({
      title: 'Caching',
    }),
    new CleanWebpackPlugin({cleanStaleWebpackAssets: false}),
    new ScriptExtHtmlWebpackPlugin({ //结合`script-ext-html-webpack-plugin`插件可将runtime文件内联进html文件
      inline: /runtime~.+\.js$/  //正则匹配runtime文件名
    })
  ],
  optimization: {
    runtimeChunk: true,
    splitChunks: {
      chunks: 'all'
    }
  }
};