Heroku部署Node.js项目时multer与multer-gridfs-storage依赖冲突

问题详情 #

部署Node.js项目到Heroku时，安装依赖阶段触发如下错误：

remote: -----> Installing dependencies
remote:        Installing node modules
remote:        npm ERR! code ERESOLVE
remote:        npm ERR! ERESOLVE could not resolve
remote:        npm ERR!
remote:        npm ERR! While resolving: multer-gridfs-storage@5.0.2
remote:        npm ERR! Found: multer@1.4.5-lts.1
remote:        npm ERR! node_modules/multer
remote:        npm ERR!   multer@"^1.4.5-lts.1" from the root project
remote:        npm ERR!
remote:        npm ERR! Could not resolve dependency:
remote:        npm ERR! peer multer@"^1.4.2" from multer-gridfs-storage@5.0.2
remote:        npm ERR! node_modules/multer-gridfs-storage
remote:        npm ERR!   multer-gridfs-storage@"^5.0.2" from the root project
remote:        npm ERR!
remote:        npm ERR! Conflicting peer dependency: multer@1.4.4
remote:        npm ERR! node_modules/multer
remote:        npm ERR!   peer multer@"^1.4.2" from multer-gridfs-storage@5.0.2
remote:        npm ERR!   node_modules/multer-gridfs-storage
remote:        npm ERR!     multer-gridfs-storage@"^5.0.2" from the root project
remote:        npm ERR!
remote:        npm ERR! Fix the upstream dependency conflict, or retry
remote:        npm ERR! this command with --force, or --legacy-peer-deps
remote:        npm ERR! to accept an incorrect (and potentially broken) dependency resolution.
remote:        npm ERR!
remote:        npm ERR! See /tmp/npmcache.fbHb6/eresolve-report.txt for a full report.
remote:
remote:        npm ERR! A complete log of this run can be found in:
remote:        npm ERR!     /tmp/npmcache.fbHb6/_logs/2022-10-22T21_00_27_665Z-debug-0.log
remote:
remote: -----> Build failed
remote:
remote:        We're sorry this build is failing! You can troubleshoot common issues here:
remote:        https://devcenter.heroku.com/articles/troubleshooting-node-deploys
remote:
remote:        If you're stuck, please submit a ticket so we can help:
remote:        https://help.heroku.com/
remote:
remote:        Love,
remote:        Heroku
remote:
remote:  !     Push rejected, failed to compile Node.js app.
remote:
remote:  !     Push failed

核心原因是multer-gridfs-storage@5.0.2的peer依赖要求multer版本为^1.4.2，但项目中使用的是multer@1.4.5-lts.1，npm的依赖解析器无法处理该版本差异引发冲突。

解决方案 #

1. 降级multer到兼容版本 #

修改package.json中的multer版本为^1.4.4（错误提示明确的兼容版本）：

"multer": "^1.4.4"

执行以下命令更新依赖并重新部署：

npm install
git add package.json package-lock.json
git commit -m "降级multer版本以解决依赖冲突"
git push heroku main

2. 启用npm的legacy-peer-deps选项 #

若不想修改依赖版本，可让npm忽略peer依赖的严格检查，两种实现方式：

• 修改package.json的install脚本：

  "scripts": {
    "install": "npm install --legacy-peer-deps",
    // 保留其他原有脚本
  }
  

• 设置Heroku环境变量：

  heroku config:set NPM_CONFIG_LEGACY_PEER_DEPS=true
  git push heroku main
  

3. 升级multer-gridfs-storage到最新版本 #

检查multer-gridfs-storage是否有更新版本支持multer@1.4.5-lts.1，将package.json中的版本替换为最新稳定版：

"multer-gridfs-storage": "^X.X.X" // 替换为实际最新版本号

执行依赖更新后重新部署：

npm install
git add package.json package-lock.json
git commit -m "升级multer-gridfs-storage版本以兼容当前multer"
git push heroku main

内容的提问来源于stack exchange，提问作者Stephen