💄 @kitql/eslint-config

To have linting & formatting in your project, you need 20 dep, files, … and it’s a pain to maintain in each project.

Here the idea is to reduce as much as possible the config on your end. (Of course, you can still tune things)

Installation

npm i -D @kitql/eslint-config eslint oxfmt

You need to install the peer dependencies you want to use (by default: eslint, oxfmt).

@kitql/eslint-config ships optional tools - install only what you want to use:

Tool	What it does	Install
eslint	Linter (svelte rules, pnpm catalog rules, custom rules)	`npm i -D eslint`
oxfmt	Formatter (Rust); every file type, incl. `.svelte`	`npm i -D oxfmt`
oxlint	Faster linter (Rust); covers most JS/TS rules	`npm i -D oxlint`
tsgolint	Type-aware lint rules for oxlint	`npm i -D oxlint-tsgolint`

That’s it: no public-hoist-pattern and no need to list every eslint plugin in your own package.json. @kitql/eslint-config ships them as its own dependencies and resolves them internally.

eslint config

import { kitql } from '@kitql/eslint-config'

/** @type { import('eslint').Linter.Config[]} */
const config = [
  ...kitql(),
  {
    name: 'app:rules',
    rules: {
      // Some custom things?
    },
  },
]

export default config

You can check your config running this tool

npx @eslint/config-inspector

oxlint config

{
  "$schema": "./node_modules/oxlint/configuration_schema.json",
  "extends": ["./node_modules/@kitql/eslint-config/.oxlintrc.json"],
  "rules": {
    // Some custom things?
  },
}

The shipped config enables @e18e/eslint-plugin + eslint-plugin-depend for modern-JS suggestions (prefer Array.at, Date.now, URL.canParse, …) and the correctness category at error level.

oxfmt config

oxfmt has no extends, so pick one of these two.

oxfmt.config.ts (recommended): import the shipped config, override what you need, and get kitql updates for free.

import kitql from '@kitql/eslint-config/.oxfmtrc.json' with { type: 'json' }

const { groups, customGroups } = kitql.sortImports
const at = groups.indexOf('aliases')

export default {
  ...kitql,
  // tailwind v4 custom classes (path relative to this file)
  sortTailwindcss: { stylesheet: './src/app.css' },
  sortImports: {
    ...kitql.sortImports,
    // one more import group, just before the `$*` aliases
    groups: [...groups.slice(0, at), 'my-lib', ...groups.slice(at)],
    // first match wins, so it goes before kitql's catch-all groups
    customGroups: [{ groupName: 'my-lib', elementNamePattern: ['@my-org/**'] }, ...customGroups],
  },
}

The spread is shallow: spread kitql.sortImports again when you change a key inside it. No defineConfig: the json import widens strings and fails its types.

.oxfmtrc.json: copy @kitql/eslint-config/.oxfmtrc.json and edit your copy (no kitql updates).

kitql-lint uses oxfmt.config.ts first, then .oxfmtrc.json. The oxc VS Code extension finds both. svelte: true needs svelte installed. Other tweaks: per-file overrides. All options: node_modules/oxfmt/configuration_schema.json.

ignore things with

.prettierignore is read by oxfmt and by the eslint config (the name stays for compatibility).

.DS_Store
node_modules
/build
/.svelte-kit
/package
.env
.env.*
!.env.example

# Ignore files for PNPM, NPM and YARN
package.json
pnpm-lock.yaml
package-lock.json
yarn.lock

# Ignore files that are project specific
/db
/src/lib/ROUTES.ts

Add this to your `package.json`

scripts: {
  "//// ---- BEST PRACTICES ---- ////": "",
  "lint": "kitql-lint",
  "format": "kitql-lint -f",
}

Picking which tools run

By default, kitql-lint runs eslint + oxfmt. Use --tools (-t) to change that:

# default - eslint + oxfmt
kitql-lint

# 🦀 add oxlint (with type-aware rules) - the recommended combo for kitql / sveltekit projects.
# eslint stays around for svelte + pnpm catalog rules.
kitql-lint -t oxlint,tsgolint,oxfmt,eslint

# 🦀 pure oxc - no eslint.
# you lose: .svelte linting, pnpm catalog rules.
kitql-lint -t oxlint,tsgolint,oxfmt

In the recommended combo, you’ll have oxlint and eslint both linting .ts/.js files. To avoid duplicate work, enable the oxlint integration in your eslint config:

import { kitql } from '@kitql/eslint-config'

export default [...kitql({ oxlint: { enable: true } })]

That disables in eslint every rule oxlint already covers - you only pay for the svelte/pnpm rules that oxlint can’t replace yet.