拆分三方包

// 安装依赖
npm install compression-webpack-plugin
// vue.config.js文件
const CompressionWebpackPlugin = require('compression-webpack-plugin')
module.exports = {
    configureWebpack: config =>{
        let plugins = [
            new CompressionWebpackPlugin({
                algorithm: 'gzip', //压缩方式
                // test: productionGzipExtensions, //匹配压缩文件
                threshold: 2048  //对大于10k压缩
            })
        ]
        if (process.env.NODE_ENV === 'production') {
            config.mode = "production";
            config.plugins = [...config.plugins, ...plugins]
        }else{
            config.mode = "development"
        }
        Object.assign(config, {
            externals: {
                vue: 'Vue',  
                element: 'ElementUI', 
                echarts: 'echarts'
            }
        })
    }
}

// npm run build后在dist中的index.html文件
<!-- 生产环境版本，优化了尺寸和速度 -->
<script src="https://cdn.jsdelivr.net/npm/vue"></script>
<!-- 引入样式 -->
<link rel="stylesheet" href="https://unpkg.com/element-ui/lib/theme-chalk/index.css">
<!-- 引入组件库 -->
<script src="https://unpkg.com/element-ui/lib/index.js"></script>
<script src="https://lib.baomitu.com/echarts/5.3.1/echarts.common.min.js"></script>