Linters · tidy

tidy formats. It has no rules and will not tell you about an unused variable. Keep a linter beside it, and make sure that linter has no opinions about layout — otherwise one tool rewrites what the other just wrote, and the loop never settles.

The rule is Prettier's: turn off every stylistic rule in the linter.

ESLint

eslint-config-prettier turns them off, and works unchanged for tidy, because the style is the same. Nothing about your existing setup has to move.

Shell

$ npm install --save-dev eslint-config-prettier

eslint.config.js

import js from "@eslint/js";
import prettier from "eslint-config-prettier";

export default [js.configs.recommended, prettier];

Put it last, so it switches off the formatting rules that the configs before it turned on.

Do not use eslint-plugin-prettier. It runs the formatter as a lint rule, so every formatting difference becomes an error in your editor's problem list — and the formatting goes back through Node, which is the cost tidy exists to remove. Format with tidy up, lint with ESLint, and keep them apart.

Biome

Biome lints and formats. Use one of the two for formatting, not both:

biome.json

{
  "formatter": { "enabled": false },
  "linter": { "enabled": true }
}

With its formatter off, Biome lints and tidy formats.

Others

oxlint ships no stylistic rules, so there is nothing to turn off. Stylelint dropped its own in version 15, so recent versions need nothing either.

Order

Lint first, format second:

Shell

$ eslint . && tidy check .

A lint autofix rewrites syntax, not layout, so it can leave code unformatted. Formatting afterwards cleans up after it. The other order leaves you with a formatted file that the next autofix will unformat.