Webpack 5.84.0+ 出现flatMap is not a function错误，如何解决？

我在学习Webpack教程时，刚尝试编译就遇到错误。安装Webpack和webpack-cli后，执行构建脚本出现以下报错：

[webpack-cli] TypeError: ["webpack.config",".webpack/webpack.config",".webpack/webpackfile"].flatMap is not a function
    at WebpackCLI.loadConfig (C:\Users\xxxxxxxxxx\Documents\Repositories\webpack-starter\node_modules\webpack-cli\lib\webpack-cli.js:1439:15)
    at WebpackCLI.createCompiler (C:\Users\xxxxxxxxxxx\Documents\Repositories\webpack-starter\node_modules\webpack-cli\lib\webpack-cli.js:1714:33)
    at WebpackCLI.runWebpack (C:\Users\xxxxxxxxxxx\Documents\Repositories\webpack-starter\node_modules\webpack-cli\lib\webpack-cli.js:1810:31)
    at Command.makeCommand (C:\Users\xxxxxxxxxxx\Documents\Repositories\webpack-starter\node_modules\webpack-cli\lib\webpack-cli.js:892:32)
    at Command.listener [as _actionHandler] (C:\Users\xxxxxxxx\Documents\Repositories\webpack-starter\node_modules\webpack-cli\node_modules\commander\lib\command.js:482:17)
    at actionResult._chainOrCall (C:\Users\xxxxxxxxxxx\Documents\Repositories\webpack-starter\node_modules\webpack-cli\node_modules\commander\lib\command.js:1283:65)
    at Command._chainOrCall (C:\Users\xxxxxxxxxxxx\Documents\Repositories\webpack-starter\node_modules\webpack-cli\node_modules\commander\lib\command.js:1177:12)
    at Command._parseCommand (C:\Users\xxxxxxxxxxxx\Documents\Repositories\webpack-starter\node_modules\webpack-cli\node_modules\commander\lib\command.js:1283:27)
    at hookResult._chainOrCall (C:\Users\xxxxxxxxxx\Documents\Repositories\webpack-starter\node_modules\webpack-cli\node_modules\commander\lib\command.js:1081:27)
    at Command._chainOrCall (C:\Users\xxxxxxxxxxx\Documents\Repositories\webpack-starter\node_modules\webpack-cli\node_modules\commander\lib\command.js:1177:12)
npm ERR! code ELIFECYCLE
npm ERR! errno 2
npm ERR! webpack-starter@1.0.0 build: `webpack --mode production`       
npm ERR! Exit status 2
npm ERR!
npm ERR! Failed at the webpack-starter@1.0.0 build script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     C:\Users\xxxxxxxx\AppData\Roaming\npm-cache\_logs\2023-05-26T14_49_54_605Z-debug.log

将Webpack从5.84.0降级到5.70.0、webpack-cli从5.0.1降级到4.9.2后错误消失。请问能否使用最新版本完成简单npm构建，还是这是无法修复的破坏性变更？

问题原因与解决方案 #

这个报错的核心原因是Node.js版本过低：Array.flatMap()是Node.js 11及以上才支持的API，你当前使用的Node.js版本不兼容该方法，导致webpack-cli代码执行失败。

完全可以使用最新版本的Webpack和webpack-cli完成构建，无需降级，只需执行以下步骤：

• 升级Node.js版本到16.x及以上（Webpack 5官方推荐最低版本为10.13.0，但webpack-cli 5.x对Node.js版本要求更高，建议直接安装最新LTS版本）
• 升级后清理旧依赖并重新安装：
  1. 删除项目根目录下的node_modules文件夹和package-lock.json文件
  2. 执行npm install重新安装依赖
  3. 再次运行构建命令npm run build

这并非Webpack的破坏性变更，只是新版本webpack-cli依赖了更高版本Node.js的原生API，升级Node.js即可正常使用最新版Webpack套件。

内容的提问来源于stack exchange，提问作者Robert Carmichael