问题
在使用vue 3运行web3钱包项目时，突然出现以下报错信息：
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: { "crypto": require.resolve("crypto-browserify") }'
- install 'crypto-browserify'
If you don't want to include a polyfill, you can use an empty module like this:
resolve.fallback: { "crypto": false }
@ ./node_modules/ethereumjs-wallet/dist.browser/index.js 175:19-42
@ ./node_modules/babel-loader/lib/index.js??clonedRuleSet-40.use[0]!./node_modules/vue-loader/dist/index.js??ruleSet[0].use[0]!./src/components/WalletsAPI.vue?vue&type=script&setup=true&lang=js 3:0-42 21:19-39 52:15-20
@ ./src/components/WalletsAPI.vue?vue&type=script&setup=true&lang=js 1:0-213 1:0-213 1:214-416 1:214-416
@ ./src/components/WalletsAPI.vue 2:0-72 3:0-67 3:0-67 6:49-55
@ ./node_modules/babel-loader/lib/index.js??clonedRuleSet-40.use[0]!./node_modules/vue-loader/dist/index.js??ruleSet[0].use[0]!./src/App.vue?vue&type=script&setup=true&lang=js 1:0-53 9:6-16
@ ./src/App.vue?vue&type=script&setup=true&lang=js 1:0-200 1:0-200 1:201-390 1:201-390
@ ./src/App.vue 2:0-65 3:0-60 3:0-60 6:49-55
@ ./src/main.js 2:0-28 3:10-13根据上面的提示，webpack5默认移除了node.js的核心模块，要使用的话需要手动引入。
解决办法
首先我们需要先按照下面的命令安装一个插件node-polyfill-webpack-plugin，用于在浏览器环境下模拟nodejs核心模块的功能：
$ npm i node-polyfill-webpack-plugin然后再安装crypto-browserify：
$ npm i crypto-browserify最后在修完我们项目中的vue.config.js文件
const { defineConfig } = require('@vue/cli-service')
const NodePolyfillPlugin = require("node-polyfill-webpack-plugin") // add
module.exports = defineConfig({
transpileDependencies: true,
configureWebpack:{ // add
plugins:[new NodePolyfillPlugin()]
}
})声明：本作品采用署名-非商业性使用-相同方式共享 4.0 国际 (CC BY-NC-SA 4.0)[1]进行许可，使用时请注明出处。 Author: mengbin[2] blog: mengbin[3] Github: mengbin92[4] cnblogs: 恋水无意[5] 腾讯云开发者社区：孟斯特[6]
References
[1] 署名-非商业性使用-相同方式共享 4.0 国际 (CC BY-NC-SA 4.0): https://creativecommons.org/licenses/by-nc-sa/4.0/deed.zh
[2] mengbin: mengbin1992@outlook.com
[3] mengbin: https://mengbin.top
[4] mengbin92: https://mengbin92.github.io/
[5] 恋水无意: https://www.cnblogs.com/lianshuiwuyi/
[6] 孟斯特: https://cloud.tencent.com/developer/user/6649301
