React Native开发环境搭建报错：执行npm start出现UnhandledPromiseRejectionWarning

解决方案步骤 #

• 检查当前Node.js版本：打开终端执行

  node -v
  

  如果输出版本低于14.0.0，说明版本过低，需要升级。
• 升级Node.js（推荐用nvm管理版本，避免权限问题）：
  • 安装nvm后，执行以下命令安装最新长期支持版（LTS）：

    nvm install --lts
    

  • 切换到刚安装的LTS版本：

    nvm use --lts
    

  • 若未使用nvm，可直接下载Node.js官网的LTS版本安装包，覆盖现有版本。
• 验证版本：再次执行node -v，确认版本≥14.0.0
• 重新启动项目：

  # Windows系统
  rd /s /q node_modules && del package-lock.json
  # macOS/Linux系统
  rm -rf node_modules package-lock.json
  
  npm install
  npm run android
  

问题原因 #

fs/promises是Node.js 14.0.0及以上版本才原生支持的内置模块，你当前使用的Node.js版本不支持该模块，导致Expo CLI启动时无法加载依赖文件，进而抛出错误。

错误日志 #

C:\Users\DELL\Desktop\project> npm run android

> project@1.0.0 android C:\Users\DELL\Desktop\project
> expo start --android

(node:3460) UnhandledPromiseRejectionWarning: Error: Cannot find module 'fs/promises'
Require stack:
- C:\Users\DELL\Desktop\project\node_modules\@expo\cli\build\src\start\doctor\typescript\TypeScriptProjectPrerequisite.js
- C:\Users\DELL\Desktop\project\node_modules\@expo\cli\build\src\start\startAsync.js
- C:\Users\DELL\Desktop\project\node_modules\@expo\cli\build\src\start\index.js
- C:\Users\DELL\Desktop\project\node_modules\@expo\cli\build\bin\cli
    at Function.Module._resolveFilename (internal/modules/cjs/loader.js:962:15)
    at Function.Module._load (internal/modules/cjs/loader.js:838:27)
    at Module.require (internal/modules/cjs/loader.js:1022:19)
    at require (internal/modules/cjs/helpers.js:72:18)
    at Object.<anonymous> (C:\Users\DELL\Desktop\project\node_modules\@expo\cli\build\src\start\doctor\typescript\TypeScriptProjectPrerequisite.js:5:40)
    at Module._compile (internal/modules/cjs/loader.js:1118:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1138:10)
    at Module.load (internal/modules/cjs/loader.js:982:32)
    at Function.Module._load (internal/modules/cjs/loader.js:875:14)
    at Module.require (internal/modules/cjs/loader.js:1022:19)
    at require (internal/modules/cjs/helpers.js:72:18)
    at Object.<anonymous> (C:\Users\DELL\Desktop\project\node_modules\@expo\cli\build\src\start\startAsync.js:15:38)
    at Module._compile (internal/modules/cjs/loader.js:1118:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1138:10)
    at Module.load (internal/modules/cjs/loader.js:982:32)
    at Function.Module._load (internal/modules/cjs/loader.js:875:14)
(Use `node --trace-warnings ...` to show where the warning was created)
(node:3460) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either
by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 1)
(node:3460) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.
PS C:\Users\DELL\Desktop\project>

内容的提问来源于stack exchange，提问作者Surya Keshub Misra