Error: Cannot find module 'webpa

但是，当你升级webpack4 ---->webpack5时，如果你的版本是webpack-cli 4*时，就会报错

Error: Cannot find module 'webpack-cli/bin/config-yargs'

"webpack": "^5.36.0",
"webpack-cli": "^4.6.0",
"webpack-dev-server": "^3.11.2"

这是，因为在webpack-cli 4*中，作者删除了config-yargs，所以会报错。

这里有两种解决方案

• 临时解决方案：将webpack-cli版本降级到webpack-cli 3*
• 终极解决方案：修改配置文件，使用webpack serve替代webpack-dev-server也就是将配置项的 "dev": "webpack-dev-server --open"改为"dev": "webpack serve --open"

{
  "name": "project",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "build": "webpack",
    "dev": "webpack serve --open"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
}