feat!: remove eslint v8 / eslintrc support and remove flat/ prefix from configs

[michaelfaith]

This change removes support for legacy rc-based configs, and moves minimum supported version to 9.0. I've also removed the deprecated /configs entry point. Please use the plugin's configs object.

Contributes to #505

[bmish]

Can you cherry-pick my commit from this PR to include the RuleTester update? Then I can close my PR.

• feat!: drop eslint v8 support #524

[michaelfaith]

Your PR removed our RuleTester, but with the vitest change (which I believe was still in PR, when your change went up), we still need to attach vitest's functions to RuleTester. So I removed the v8 specific logic from it, but left the vitest augmentation. I think this will cover what was in your change?

[bmish]

Your PR removed our RuleTester, but with the vitest change (which I believe was still in PR, when your change went up), we still need to attach vitest's functions to RuleTester. So I removed the v8 specific logic from it, but left the vitest augmentation. I think this will cover what was in your change?

@michaelfaith I just pushed this change to solve that so rule test files can use the standard RuleTester import. Look good?

[michaelfaith]

Yep! That's much cleaner. Thanks.

[bmish]

Here's some more context about the config names btw:

• feat: re-export flat configs "flat/*" #453

I think the current plan to just drop ESLint v8 / eslintrc now is fine.

[bmish]

Error: 130:29 error Can't resolve './package.json' in '/home/runner/work/eslint-plugin-eslint-plugin/eslint-plugin-eslint-plugin/docs/rules/require-meta-docs-url.md' n/no-missing-import

You can disable that lint rule for this file if necessary.

[bmish]

Example of disabling a lint rule for markdown code sample:

https://github.com/ember-cli/eslint-plugin-ember/blob/ea0e3802b9971884eab5092e07730e4a0b04d9de/eslint.config.js#L172

[michaelfaith]

Ah, I had 'n/no-missing-imports' instead of 'n/no-missing-import' doh

[michaelfaith]

Looks good now

[bmish]

Thank you!