eslint-plugin-qwik

eslint-plugin-qwik

Qwik comes with its own set of ESLint rules to help developers write better code.

Usage

Install the plugin:

npm add -D eslint-plugin-qwik
pnpm add -D eslint-plugin-qwik
yarn add -D eslint-plugin-qwik

eslint-plugin-qwik uses the tsc typechecker to type information. You must include the tsconfigRootDir in the parserOptions.

Configurations

Flat config (recommended)

// eslint.config.js
import js from '@eslint/js';
import globals from 'globals';
import tseslint from 'typescript-eslint';
import { qwikEslint9Plugin } from 'eslint-plugin-qwik';

export const qwikConfig = [
  js.configs.recommended,
  ...tseslint.configs.recommended,
  {
    languageOptions: {
      parserOptions: {
        projectService: true,
        tsconfigRootDir: import.meta.dirname,
      },
    },
  },
  {
    files: ['**/*.{js,mjs,cjs,jsx,mjsx,ts,tsx,mtsx}'],
    languageOptions: {
      globals: {
        ...globals.serviceworker,
        ...globals.browser,
        ...globals.node,
      },
    },
  },
  ...qwikEslint9Plugin.configs.recommended,
  {
    ignores: ['node_modules/*', 'dist/*', 'server/*', 'tmp/*'],
  },
];

ignores must always be the last configuration in the array. Note that in shared configs, the ignores must be defined where the config is used, not in the shared config.

Legacy config (eslint < 9)

// .eslintrc.js
module.exports = {
  env: {
    browser: true,
    es2021: true,
    node: true,
  },
  extends: [
    'eslint:recommended',
    'plugin:@typescript-eslint/recommended',
    'plugin:qwik/recommended',
  ],
  parser: '@typescript-eslint/parser',
  parserOptions: {
    tsconfigRootDir: __dirname,
    project: ['./tsconfig.json'],
    ecmaVersion: 2021,
    sourceType: 'module',
    ecmaFeatures: {
      jsx: true,
    },
  },
  plugins: ['@typescript-eslint'],
};

To ignore files, you must use the .eslintignore file.

List of supported rules

• Warn in 'recommended' ruleset — ✔️
• Error in 'recommended' ruleset — ✅
• Warn in 'strict' ruleset — 🔒
• Error in 'strict' ruleset — 🔐
• Typecheck — 💭

Rule	Description	Ruleset
qwik/valid-lexical-scope	Used the tsc typechecker to detect the capture of unserializable data in dollar ($) scopes.	✅ 🔐 💭
qwik/use-method-usage	Detect invalid use of use hook.	✅ 🔐
qwik/no-react-props	Disallow usage of React-specific className/htmlFor props.	✅ 🔐
qwik/loader-location	Detect declaration location of loader$.	✔️ 🔐
qwik/prefer-classlist	Enforce using the classlist prop over importing a classnames helper. The classlist prop accepts an object { [class: string]: boolean } just like classnames.	✔️ 🔐
qwik/jsx-no-script-url	Disallow javascript: URLs.	✔️ 🔐
qwik/jsx-key	Disallow missing key props in iterators/collection literals.	✔️ 🔐
qwik/unused-server	Detect unused server$() functions.	✅ 🔐
qwik/jsx-img	For performance reasons, always provide width and height attributes for <img> elements, it will help to prevent layout shifts.	✔️ 🔐
qwik/jsx-a	For a perfect SEO score, always provide href attribute for <a> elements.	✔️ 🔐
qwik/no-use-visible-task	Detect useVisibleTask$() functions.	✔️ 🔒