According to the example repo the rootDir is invalid. If you swallow the error, sane is a no-op and the user -- who potentially by mistake passed the wrong path -- will never know about the error.

I think this should be solved by the caller. Just do fs.stat, make sure it exists, and is a directory and don't call sane if it's not.

I commented on your watchpack PR with suggestions. Closing but open to discuss this.