fix(RemoteAuth): correct auth zip directory based on writable of cwd

[huynhtuandat05december]

Description

Fixes ENOENT failures when RemoteAuth is paired with remote stores like wwebjs-aws-s3 or wwebjs-mongo.

Since #3375, the session zip is written to this.dataPath. However, store adapters (S3, GridFS) open the zip by its relative filename (e.g. RemoteAuth-<sessionId>.zip), which Node resolves against process.cwd(). When dataPath and cwd differ, the upload step can't find the file and crashes:

node:internal/process/promises:394
  triggerUncaughtException(err, true /* fromPromise */);
[Error: ENOENT: no such file or directory, open 'RemoteAuth-XXXXXXXXXX.zip'] {
  errno: -2,
  code: 'ENOENT',
  syscall: 'open',
  path: 'RemoteAuth-XXXXXXXXXX.zip'
}
Node.js v24.15.0
ELIFECYCLE  Command failed with exit code 1.

This PR resolves a single zipDir at construction time so the zip lives where store adapters expect it, while preserving #3375 Lambda support:

• If process.cwd() is writable => use it. The zip lands at the path store adapters resolve relative filenames against, so S3 / GridFS uploads succeed.
• Otherwise => fall back to this.dataPath (Lambda's read-only root filesystem, only /tmp writable — Store RemoteAuth ZIP files inside dataPath #3375).

Both the archiver output path (backup => upload to S3 / Mongo) and the extract path (download => restore) use this.zipDir, so the write and read locations stay consistent.

Related Issue(s)

closes #5781

Testing Summary

Test Details

• PNPM:

pnpm add github:huynhtuandat05december/whatsapp-web.js#fix/remote-auth-zip-directory

• YARN:

yarn add github:huynhtuandat05december/whatsapp-web.js#fix/remote-auth-zip-directory

• NPM:

npm install github:huynhtuandat05december/whatsapp-web.js#fix/remote-auth-zip-directory

Environment

• Machine OS: macOS 15
• Phone OS: iOS 26.0
• Library Version: 1.34.6 - main branch with latest commit hash is 211205363c06b0a4d35f0047adce07da937ffc19
• WhatsApp Web Version: 2.3000.1017054665
• Browser Type and Version: Chromium 120
• Node Version: 24.15.0

Type of Change

• Dependency change (package changes such as removals, upgrades, or additions)
• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Non-code change (documentation, README, etc.)

Checklist

• My code follows the style guidelines of this project.
• All new and existing tests pass (npm test).
• Typings (e.g. index.d.ts) have been updated if necessary.
• Usage examples (e.g. example.js) / documentation have been updated if applicable.

[jusufalwi]

PR #201726 - fix(RemoteAuth): correct auth zip directory based on writable of cwd

Looked at the change. The approach makes sense - checking process.cwd() writability at startup and falling back to dataPath if not.

One thing to consider: the fallback is silent. If cwd becomes unwritable after initialization (or if someone is debugging why zips ended up in a different location), there's no indication it happened. Not a blocker, but a log.warn or similar would help.

Also worth noting: if dataPath is also not writable, the error will surface later during compressSession rather than at construction. The error message at that point won't be obvious. Again, not a blocker for this fix since you're improving the common case, but something to keep in mind.

The core logic looks correct. Ship it.