fix(codegen): scan symlinked js source directories

[sayem314]

Summary:

Fix React Native codegen directory expansion when a configured JS source directory is a symlink.

combine-js-to-schema currently checks source entries with fs.lstatSync(file).isDirectory(). lstatSync does not follow symlinks, so a symlinked directory is treated as a file and codegen does not scan its contents.

This can happen with package managers such as pnpm when a library sets codegenConfig.jsSrcsDir to a symlinked package directory. Codegen can then emit an empty schema/header even though valid TurboModule or NativeComponent specs exist inside that directory.

This changes the directory check to fs.statSync(file).isDirectory(), which follows symlinks, and adds a regression test for symlinked source directories.

Changelog:

[GENERAL] [FIXED] - Fix codegen scanning of symlinked JS source directories

Test Plan:

Added a Jest regression test for combine-js-to-schema with a symlinked directory.

Ran:

git diff --check

Also verified the Node filesystem behavior locally:

node -e "const fs=require('fs'), os=require('os'), path=require('path'); const d=fs.mkdtempSync(path.join(os.tmpdir(),'rn-codegen-symlink-')); const real=path.join(d,'real'); const link=path.join(d,'link'); fs.mkdirSync(real); fs.symlinkSync(real, link, 'dir'); console.log({lstatIsDir: fs.lstatSync(link).isDirectory(), statIsDir: fs.statSync(link).isDirectory()}); fs.rmSync(d,{recursive:true,force:true});"

Output:

{ lstatIsDir: false, statIsDir: true }

Could not run Jest locally in this checkout because yarn/dependencies were not installed in the environment.

[meta-cla]

Hi @sayem314!

Thank you for your pull request and welcome to our community.

Action Required

In order to merge any pull request (code, docs, etc.), we require contributors to sign our Contributor License Agreement, and we don't seem to have one on file for you.

Process

In order for us to review and merge your suggested changes, please sign at https://code.facebook.com/cla. If you are contributing on behalf of someone else (eg your employer), the individual CLA may not be sufficient and your employer may need to sign the corporate CLA.

Once the CLA is signed, our tooling will perform checks and validations. Afterwards, the pull request will be tagged with CLA signed. The tagging process may take up to 1 hour after signing. Please give it that time before contacting us about it.

If you have received this in error or have any questions, please contact us at cla@meta.com. Thanks!

[meta-cla]

Thank you for signing our Contributor License Agreement. We can now accept your code for this (and any) Meta Open Source project. Thanks!