- [2b395b9f] Fix command to lint markdown in `CONTRIBUTING.md`
- [fed4c86c] Re-activate JSDoc ESLint plugin and fix linting issues (As
far as I remember, we deactivated it when we upgraded to ESLint 9
because it was not compatible with it. But its now.)
- [a3d2064b] Refactor ESLint config to use `defineConfig` and
`globalIgnores` ([these are like new
defaults](https://eslint.org/blog/2025/03/flat-config-extends-define-config-global-ignores/))
- [a3d2064b] Replace `eslint-plugin-import` with
`eslint-plugin-import-x`
(https://github.com/es-tooling/module-replacements/blob/main/docs/modules/eslint-plugin-import.md)
- [86a185b6] Switch Stylelint config to flat format and simplify
Stylelint scripts (like we already did for ESLint and prettier)
- [f5a2c541] Fix some typos
Main point was to enable ESLint `dot-notation` and `no-unneeded-ternary`
rules for more code consistency.
I took the occasion to add two minor commits:
- Fix a problem found by running `test:spelling
- Minor dependency update
It wouldn't be a problem if the PR didn't arrive in the next release,
the changes are cosmetic.
Since PR #3551 was not yet complete, I made my own attempt.
1. Update to ESLint v9.
2. Replace deprecated `.eslintrc.json` and `.eslintignore` by flat
config `eslint.config.mjs`.
3. Adapt `check_config.js` to use flat config.
4. Since `eslint-plugin-import` still doesn't support ESLint v9 I
removed it. We can add it back when it does support v9.
5. Run tests `npm run check:js` and `npm run config:check`.
6. In order not to overload this PR, I have not yet activated more
additional rules - there are some useful ones in the new plugin
`@eslint/js`.
@bugsounet, please don't take it as an offence that I have created a
competing PR. The migration to ESLint v9 has been burning under my nails
for some time.
