feat: support eslint 9

[Smrtnyk]

Also increased major version

I tested this in my repo https://github.com/Smrtnyk/Firetable where I am using eslint 9 and flat config, and it works fine with these changes

I ran the tests:all command it also passes all the tests.

[getify]

The rest LGTM, thanks! :)

[getify]

Code LGTM.

We may need some docs changes... and we also should figure out how v9+ handle the config presets (given that other breakage you were discussing).

[Smrtnyk]

Code LGTM.

We may need some docs changes... and we also should figure out how v9+ handle the config presets (given that other breakage you were discussing).

I can help you with that.
Do you want it to be part of this PR or separate?
I believe this PR is enough to get the people going and unblock them from eslint 9 upgrade (such as myself at the company I work for), and then I can contribute another PR with flat config preset.
I believe that flat config preset could require some restructuring of the plugin object, so it might involve more code changes.
Either way I want to help, so let me know what you prefer :)

[getify]

removing the preset would be a "breaking change", which sort of defeats the intent here of "fixing" the plugin to keep working without such forking/breakage.

so I would like to at least understand better what other changes are necessary to preserve presets before wrapping this up.

it might well belong in a separate PR, but I think we need that to land before a new "release"... so I just want to have a better sense of the "scope" of such work before we finalize this PR.

also, if this plugin is now used/activated/configured differently in v9+, I want to make sure the docs have a mention of that difference.

[Smrtnyk]

removing the preset would be a "breaking change", which sort of defeats the intent here of "fixing" the plugin to keep working without such forking/breakage.

so I would like to at least understand better what other changes are necessary to preserve presets before wrapping this up.

it might well belong in a separate PR, but I think we need that to land before a new "release"... so I just want to have a better sense of the "scope" of such work before we finalize this PR.

also, if this plugin is now used/activated/configured differently in v9+, I want to make sure the docs have a mention of that difference.

I think we can leave your preset as it is
and add a new one maybe called getify-says/flat.
I had a bit of a look at how eslint promise plugin did this
They have entries for both legacy and flat configs
https://github.com/eslint-community/eslint-plugin-promise/blob/main/index.js#L51
I tried something like this but there were some exceptions in the eslint server and cli linter, which made me starting to restructure the current plugin object.
I think exceptions came due to some self referencing objects.

How I used this plugin with eslint 9 when testing was like this:
when I removed the plugins array which you aasked about, I continued using getify-says preset, but I added proper arrows plugin manually myself to the plugins object in my flat config.
After I reverted the plugins change in getify-says preset, I had to remove it from my flat config and manually declare the plugin + rules.

I could push a separate commit that adds the preset and required refactoring (if needed) and then we can discuss it
whether it is acceptable solution for you or not

Regarding the docs, I am not a native english speaker but I can give it a try

[Smrtnyk]

I have pushed a separate second commit, that adds a flat config preset
you can see how it is used in here Smrtnyk/Firetable@be20260#diff-a32a0887ed9d1d707bbb3b845b7df7fd40e673c47e7b60a3ebd896b68d3b8839R25

If that is fine for you I can then add some docs for this

[Smrtnyk]

btw I noticed that there is no CI build on PR branches.
I see that there is a travis config file but I am not able to see the builds.
I would feel more comfortable if there was a build and test github action running when I push to the branch.
I am building and running tests locally, but still.
If you are open for a small PR to setup a github action to run build and test I can contribute

[getify]

yes, happy to look at any and all contributions, especially helpful ideas like the CI stuff. :)

[Smrtnyk]

yes, happy to look at any and all contributions, especially helpful ideas like the CI stuff. :)

added a simple workflow in #39
tested it locally using act and docker, seems like it works fine

[Smrtnyk]

@getify In second commit I have updated the readme and added a flat config entry for the getify-says preset
I have tested it in my repo https://github.com/Smrtnyk/Firetable/blob/flat-config-arrow-functions-eslint-plugin/eslint.config.js#L25 and it works nice

[getify]

This is looking good, appreciate it. Just a few minor tweaks.

[Smrtnyk]

This is looking good, appreciate it. Just a few minor tweaks.

tnx for the feedback Kyle
I have force pushed the requested changes to the last commit

[getify]

LGTM!

[getify]

NOTE: I'll be delaying publishing this updated version on npm for a bit, just to give us time to get some feedback from folks if they try it.