Files passed to --ignore are also watched

[dahjelle]

Bug Report

Current Behavior
I was hitting an error message of "System limit for number of file watchers reached", and it turns out that this was because I was doing something like:

npx babel . --out-dir=../es5 --watch --ignore="node_modules"

But, since --ignore was not getting passed to chokidar, it was trying to watch the entire node_modules directory—hence the error!

Expected behavior/code
I would expect --watch to also respect the --ignore option.

Babel Configuration (.babelrc, package.json, cli command)

module.exports = {
  presets: ["@babel/env"],
  sourceType: "script"
};

Environment

• Babel version(s): 7.3.3
• Node/npm version: 10.15.1/6.8.0
• OS: CentOS 7.5
• Monorepo: no
• How you are using Babel: cli

Possible Solution
I attempted but failed in a patch: #9559 This failed as chokidar uses globs for their --ignored flag and Babel uses RegExp.

Is there another way to avoid the issue? I recognize it is more usual to run babel against a src directory or the like…but one doesn't always have that luxury on legacy code.

Thanks!

[babel-bot]

Hey @dahjelle! We really appreciate you taking the time to report an issue. The collaborators
on this project attempt to help as many people as possible, but we're a limited number of volunteers,
so it's possible this won't be addressed swiftly.

If you need any help, or just have general Babel or JavaScript questions, we have a vibrant Slack
community that typically always has someone willing to help. You can sign-up here
for an invite.

[nicolo-ribaudo]

I think that chokidar's ignored option can be a function: we can reuse the same function we use to decide wether or not a file should be compiled.

[Kacppian]

Can I pick this up?

[danez]

Sure feel free.

[steve-taylor]

--ignore also doesn't work when building