eslint.config.(js|mjs|cjs) is required for ESLint v9 and above

[tonypaulbarker]

Steps to repdoruce

Run npm run lint:js

Results in the output:

Oops! Something went wrong! :(

ESLint: 9.16.0

ESLint couldn't find an eslint.config.(js|mjs|cjs) file.

From ESLint v9.0.0, the default configuration file is now eslint.config.js.
If you are using a .eslintrc.* file, please follow the migration guide
to update your configuration file to the new format:

https://eslint.org/docs/latest/use/configure/migration-guide

Proposted resolution

Add a minimal eslint.config.mjs file.

Note: For me, the tool from the above migration-guide led to errors, which may be valid.

import path from "node:path";
import { fileURLToPath } from "node:url";
import js from "@eslint/js";
import { FlatCompat } from "@eslint/eslintrc";

const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);
const compat = new FlatCompat({
    baseDirectory: __dirname,
    recommendedConfig: js.configs.recommended,
    allConfig: js.configs.all
});
export default [...compat.extends("../../../core/.eslintrc.json")];

This minimal config below works to get the js lint to run for me, but I don't think it is importing the Drupal rules, we should confirm the output of the linter is as expected and picking up the rules from the Drupal core file.

import globals from "globals";
import pluginJs from "@eslint/js";


/** @type {import('eslint').Linter.Config[]} */
export default [
  {languageOptions: { globals: globals.browser }},
  pluginJs.configs.recommended,
];

[andybroomfield]

Drupal (10) uses eslint 8. I was able to run this on localgov_alert_banner using npx eslint@8
See localgovdrupal/localgov_alert_banner#404

[tonypaulbarker]

Thanks @andybroomfield that's a useful clue. Perhaps it bumped to 9 along the way to resolve some other dependencies.

[tonypaulbarker]

I see similar errors with ESLint 8 and ESLint 9 with the generated code so I think it will be on the right lines.

---

Oops! Something went wrong! :(

ESLint: 8.57.1

ESLint couldn't find the config "airbnb-base" to extend from. Please check that the name of the config is correct.

[andybroomfield]

I think that might need to be installed by going to web/core and running npm install there.
There is also a branch to add front end tooling to ddev / lando.
localgovdrupal/localgov_project#184