lint-config

@ycookiey/lint-config — a shared lint config for TypeScript and React that uses oxlint as the main linter and ESLint for the rules oxlint does not have.

Install

npm i -D @ycookiey/lint-config oxlint eslint typescript

Requires oxlint 1.85 or later, ESLint 10 or later, and Node.js 22.13 or later.

oxlint

.oxlintrc.json:

{
  "$schema": "https://raw.githubusercontent.com/oxc-project/oxc/main/npm/oxlint/configuration_schema.json",
  "extends": ["./node_modules/@ycookiey/lint-config/oxlint/.oxlintrc.json"],
  "ignorePatterns": ["**/*.d.ts"]
}

oxlint's extends does not carry over the ignorePatterns of the extended config (checked with oxlint 1.85). To keep this config's ignore patterns, such as **/*.d.ts, repeat them in your own config.

Next.js

Also extend the Next.js config:

{
  "extends": [
    "./node_modules/@ycookiey/lint-config/oxlint/.oxlintrc.json",
    "./node_modules/@ycookiey/lint-config/oxlint/next/.oxlintrc.json"
  ]
}

ESLint

eslint.config.mjs (flat config):

import lintConfig from '@ycookiey/lint-config/eslint';
export default [
  ...lintConfig,
  // your project's overrides
];

In test files (*.test.*, *.spec.*, and files under __tests__/, test-utils/ and tests/), the function passed to it / test is limited to 80 lines, not counting blank lines and comment-only lines (@ycookiey/max-test-case-lines). The length of a describe is not limited.

Strict config (opt-in)

The base config plus rules that need type information. It is an ES module, so load it with import. When loaded with require from CommonJS, the config is in .default.

import lintConfig from '@ycookiey/lint-config/eslint-strict';
export default [
  ...lintConfig,
  {
    languageOptions: {
      parserOptions: { projectService: true, tsconfigRootDir: import.meta.dirname },
    },
  },
];

Rules it adds:

| rule | what it checks | |---|---| | @typescript-eslint/naming-convention | boolean variables start with is / should / has / can / did / will, interfaces have no I prefix, and more | | @typescript-eslint/switch-exhaustiveness-check | a switch over a union handles every member; a switch over a non-union type has a default (requireDefaultForNonUnion) | | @typescript-eslint/no-floating-promises | every Promise is awaited or has its rejection handled | | @typescript-eslint/promise-function-async | a function that returns a Promise is async, so it always reports failure as a rejection | | @eslint-react/no-leaked-conditional-rendering | the left side of && in JSX cannot render a stray value such as 0 (judged from types; booleans are not reported) |