fix: EMFILE errors

[nzakas]

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What is the purpose of this pull request? (put an "X" next to an item)

[ ] Documentation update
[x] Bug fix (template)
[ ] New rule (template)
[ ] Changes an existing rule (template)
[ ] Add autofix to a rule
[ ] Add a CLI option
[ ] Add something to the core
[ ] Other, please explain:

What changes did you make? (Give an overview)

File read operations that throw an EMFILE or ENFILE error will be automatically retried.

I also added a test that runs only in CI to save us time locally. There was an error with the abort handling that I had to fix in order to make the test pass.

fixes #18301

Is there anything you'd like reviewers to focus on?

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[nzakas]

I could use some help understanding what is going on with the lint error. Linting passes locally, so it's difficult for me to debug.

[nzakas]

Looks like a bug in eslint-plugin-n:
eslint-community/eslint-plugin-n#242

[mdjermanovic]

LGTM, thanks! Leaving open for a couple of days if anyone else would like to review it before merging.

[fasttime]

When the EMFILE test runs locally, it will create 100000 files in tests/fixtures/emfile. If I run npm test afterwards, the whole tests/fixture directory, including the new 100000 files, will be copied to a temporary directory multiple times, because some unit tests run on a temporary copy of the fixtures directory:

eslint/tests/lib/eslint/eslint.js

Line 120 in 09675e1

shell.cp("-r", "./tests/fixtures/.", fixtureDir);

eslint/tests/lib/eslint/legacy-eslint.js

Line 105 in 09675e1

shell.cp("-r", "./tests/fixtures/.", fixtureDir);

eslint/tests/lib/cli-engine/cli-engine.js

Line 96 in 29c3595

shell.cp("-r", "./tests/fixtures/.", fixtureDir);

eslint/tests/lib/cli.js

Line 100 in ae8103d

sh.cp("-r", "./tests/fixtures/.", fixtureDir);

It seems unnecessary to copy those files, even if the EMFILE test will mostly run only in CI.

Would it be possible to delete the test files after the EMFILE test runs? Alternatively, we could create the files for the EMFILE test in a different directory in or in a temporary directory and run the test there.

[nzakas]

Moved the file creation to tmp/emfile-check.

[fasttime]

Just a note about .gitignore, then LGTM.

[nzakas]

@fasttime @mdjermanovic can you re-approve please?

[fasttime]

LGTM, thanks!

[mdjermanovic]

LGTM, thanks!