webpack版本问题造成项目启动失败

缺乏、安全感 2024-03-23 12:03 11阅读 0赞

## 问题背景： ##

在项目里使用了express库做前端的服务器，结果一运行给我报了23个errors（悲）

ERROR in ./node_modules/serve-static/index.js 19:14-37
    Module not found: Error: Can't resolve 'path' in 'D:\project\vue2\vue-permission-demo\node_modules\serve-static'
    
    BREAKING CHANGE: webpack < 5 used to include polyfills for node.js core modules by default.
    This is no longer the case. Verify if you need this module and configure a polyfill for it.
    
    If you want to include a polyfill, you need to:
            - add a fallback 'resolve.fallback: { "path": require.resolve("path-browserify") }'
            - install 'path-browserify'
    If you don't want to include a polyfill, you can use an empty module like this:
            resolve.fallback: { "path": false }
     @ ./node_modules/express/lib/express.js 81:0-40
     @ ./node_modules/express/index.js 11:0-41
     @ ./src/utils/http.js 8:0-35 66:29-37
     @ ./src/api/index.js 1:0-34 10:9-18
     @ ./node_modules/babel-loader/lib/index.js??clonedRuleSet-40.use[0]!./node_modules/@vue/vue-loader-v15/lib/index.js??vue-loader-options!./src/pages/login/index.vue?vue&type=script&lang=js& 1:0-34 12:23-28
     @ ./src/pages/login/index.vue?vue&type=script&lang=js& 1:0-205 1:221-224 1:226-428 1:226-428
     @ ./src/pages/login/index.vue 2:0-57 3:0-52 3:0-52 10:2-8     
     @ ./src/router/index.js 3:0-35 14:13-18
     @ ./src/main.js 4:0-30 9:2-8
    
    webpack compiled with 23 errors

## 问题定位 ##

可以发现这23个错大部分都是“Module not found”，经查询后发现在webpack5中移除了nodejs核心模块的polyfill自动引入，那么就会造成包的缺失。

## 解决方法 ##

1、运行下面这行指令**，**安装在 Webpack 中 Polyfill Node.js 核心模块。

npm install node-polyfill-webpack-plugin

2、在vue.config.json中进行对webpack的配置

//头部引用
    const NodePolyfillPlugin = require('node-polyfill-webpack-plugin')
     
    //加入
    configureWebpack: { 
        plugins: [new NodePolyfillPlugin()]
    }

3、在vue.config.json中手动添加（如果第2步做完后还有报错的话）

即说白了就是在externals中手动引入缺的模块

const NodePolyfillPlugin = require("node-polyfill-webpack-plugin");
    
    module.exports = {
      //调整内部的 webpack 配置
      configureWebpack: {
        plugins: [new NodePolyfillPlugin()],
        externals: {
          fs: require('fs'),
          net: require('net'),
          async_hooks: require('async_hooks')
        }
      },
      devServer: {
        proxy: {
          '/api': {
            target: 'http://localhost:3300',
            changeOrigin: true,
            pathRewrite: {
              '^/api': ''
            }
          }
        }
      }
    }