prefer-stylelint-extends-array

Prefer array form for top-level Stylelint extends declarations.

Targeted pattern scope

This rule targets Stylelint config modules such as stylelint.config.ts, stylelint.config.mjs, and .stylelintrc.js.

It focuses on top-level exported config objects, including configs wrapped in defineConfig(...).

What this rule reports

Reports extends when it is defined as a single string instead of an array.

Why this rule exists

Array form is easier to append, reorder, and review safely in shared config files.

❌ Incorrect

export default {
    extends: "stylelint-config-standard",
    rules: {},
};

✅ Correct

export default {
    extends: ["stylelint-config-standard"],
    rules: {},
};

Behavior and migration notes

This rule auto-fixes scalar string form to a single-entry array.

ESLint flat config example

import stylelint2 from "eslint-plugin-stylelint-2";

export default [stylelint2.configs.configuration];

When not to use it

Do not use this rule if your repository intentionally enforces scalar extends syntax in every Stylelint config file.

Package documentation

Stylelint package documentation:

Rule catalog ID: R021

Further reading

• Stylelint extends