Legacy eslint configuration

[michal-murawski-90poe]

Hello!

We have a case where we are still on the eslint@8.5* version of the eslint in our monorepo. I was trying to run both oxlint and eslint with the plugin:oxlint/recommended plugin in a few packages, but it seems like there is no difference between running eslint with or without the plugin.

In the docs, there is only information about detecting the .oxlintrc.json within the modern eslint.config.js. What about the legacy one? Could someone point me to a probable issue or solution? Some packages will require using both for some time (until specific rules are implemented), and I would love to tackle it as gracefully as possible.

Best,\micky

[Sysix]

no difference between running eslint with or without the plugin

Could you please give a small, reproducible setup? I expect manually configured rules will not be disabled.

What about the legacy one? Could someone point me to a probable issue or solution?

Personally, I do not want spent time to support a deprecated format.
Some problems which I found when exploring the possibility:

JSON Format

Can't include JS, renaming it to a JS file will break the users' setup.
Implementing it via extends will probably not disable manually configured rules.

overrides

buildFromOxlintConfigFile will output an array, because of oxlint overrides feature.
So for ESLintrc config format, we need to hook into 2 places:
Extend the rules block for general enabled rules.
Extend the overrides block for oxlint overrides.

// .oxlintrc.json
{
  "rules": { "no-debugger": "error" },
  "overrides": [
    { "files": ["**/*.ts"], "rules": { "no-debugger": "warn" }, }
  ]
}

Will return output for ESLint flat config:

[{
  "rules": { "no-debugger": "error" }
}, {
  "files": ["**/*.ts"], "rules": { "no-debugger": "warn" }
}]