@infernodesign/eslint-config

Shared ESLint flat config presets for Inferno Design projects.

• Autofix for formatting (aimed to be used standalone without Prettier)
• Reasonable best practices and only one line of config.
• Designed to work with TypeScript, JSX, Vue, JSON, YAML, Toml, Markdown, etc. Out-of-box.
• Uses the ESLint Flat Config for easy compilation.
• Optional React, Next.js, Svelte, UnoCSS, Astro, Solid support.
• Optional formatters support for formatting CSS, HTML, XML, etc.
• Style principle: Minimal for reading, stable for diff, consistent
  • Sorted imports, dangling commas
  • Single quotes, no semi
  • Using ESLint Stylistic
• Respects .gitignore by default
• Requires ESLint v9.5.0+

Usage

Starter Wizard

We provided a CLI tool to help you set up your project, or migrate from the legacy config to the new flat config with one command.

pnpm dlx @infernodesign/eslint-config@latest

Manual Install

If you prefer to set up manually:

pnpm i -D eslint @infernodesign/eslint-config

And create eslint.config.mjs in your project root:

// eslint.config.mjs
import { inferno } from '@infernodesign/eslint-config'

export default inferno()

If you still use some configs from the legacy eslintrc format, you can use the @eslint/eslintrc package to convert them to the flat config.

// eslint.config.mjs
import { FlatCompat } from '@eslint/eslintrc'
import { inferno } from '@infernodesign/eslint-config'

const compat = new FlatCompat()

export default inferno(
  {
    ignores: [],
  },

  // Legacy config
  ...compat.config( {
    extends: [
      'eslint:recommended',
      // Other extends...
    ],
  } )

  // Other flat configs...
)

Note that .eslintignore no longer works in Flat config, see customization for more details.

Add script for package.json

For example:

{
  "scripts": {
    "lint": "eslint",
    "lint:fix": "eslint --fix"
  }
}

IDE Support (auto fix on save)

VS Code support

Install VS Code ESLint extension

Add the following settings to your .vscode/settings.json:

{
  // Disable the default formatter, use eslint instead
  "prettier.enable": false,
  "editor.formatOnSave": false,

  // Auto fix
  "editor.codeActionsOnSave": {
    "source.fixAll.eslint": "explicit",
    "source.organizeImports": "never"
  },

  // Silent the stylistic rules in you IDE, but still auto fix them
  "eslint.rules.customizations": [
    { "rule": "style/*", "severity": "off", "fixable": true },
    { "rule": "format/*", "severity": "off", "fixable": true },
    { "rule": "*-indent", "severity": "off", "fixable": true },
    { "rule": "*-spacing", "severity": "off", "fixable": true },
    { "rule": "*-spaces", "severity": "off", "fixable": true },
    { "rule": "*-order", "severity": "off", "fixable": true },
    { "rule": "*-dangle", "severity": "off", "fixable": true },
    { "rule": "*-newline", "severity": "off", "fixable": true },
    { "rule": "*quotes", "severity": "off", "fixable": true },
    { "rule": "*semi", "severity": "off", "fixable": true }
  ],

  // Enable eslint for all supported languages
  "eslint.validate": [
    "javascript",
    "javascriptreact",
    "typescript",
    "typescriptreact",
    "vue",
    "html",
    "markdown",
    "json",
    "jsonc",
    "yaml",
    "toml",
    "xml",
    "gql",
    "graphql",
    "astro",
    "svelte",
    "css",
    "less",
    "scss",
    "pcss",
    "postcss"
  ]
}

Customization

Since v1.0, we migrated to ESLint Flat config. It provides much better organization and composition.

Normally you only need to import the antfu preset:

// eslint.config.js
import { inferno } from '@infernodesign/eslint-config'

export default inferno()

And that's it! Or you can configure each integration individually, for example:

// eslint.config.js
import { inferno } from '@infernodesign/eslint-config'

export default inferno( {
  // Type of the project. 'lib' for libraries, the default is 'app'
  type: 'lib',

  // Enable stylistic formatting rules
  // stylistic: true,

  // Or customize the stylistic rules
  stylistic: {
    indent: 2, // 4, or 'tab'
    quotes: 'single', // or 'double'
  },

  // TypeScript and Vue are autodetected, you can also explicitly enable them:
  typescript: true,
  vue: true,

  // Enable Next.js
  nextjs: true,

  // Enable Storybook
  storybook: true,

  // Enable JSDoc comment enforcement
  jsdoc: true,

  // Disable jsonc and yaml support
  jsonc: false,
  yaml: false,

  // `.eslintignore` is no longer supported in Flat config, use `ignores` instead
  ignores: [
    '**/fixtures',
    // ...globs
  ]
} )

The antfu factory function also accepts any number of arbitrary custom config overrides:

// eslint.config.js
import { inferno } from '@infernodesign/eslint-config'

export default inferno(
  {
    // Configures for antfu's config
  },

  // From the second arguments they are ESLint Flat Configs
  // you can have multiple configs
  {
    files: [ '**/*.ts' ],
    rules: {},
  },
  {
    rules: {},
  },
)

Going more advanced, you can also import fine-grained configs and compose them as you wish:

We wouldn't recommend using this style in general unless you know exactly what they are doing, as there are shared options between configs and might need extra care to make them consistent.

// eslint.config.js
import {
  combine,
  comments,
  ignores,
  imports,
  javascript,
  jsdoc,
  jsonc,
  markdown,
  nextjs,
  node,
  sortPackageJson,
  sortTsconfig,
  storybook,
  stylistic,
  toml,
  typescript,
  unicorn,
  vue,
  yaml,
} from '@infernodesign/eslint-config'

export default combine(
  ignores(),
  javascript( /* Options */ ),
  comments(),
  node(),
  jsdoc(),
  imports(),
  nextjs(),
  storybook(),
  unicorn(),
  typescript( /* Options */ ),
  stylistic(),
  vue(),
  jsonc(),
  yaml(),
  toml(),
  markdown(),
)

Check out the configs and factory for more details.

Thanks to sxzz/eslint-config for the inspiration and reference.

Plugins Renaming

Since flat config requires us to explicitly provide the plugin names (instead of the mandatory convention from npm package name), we renamed some plugins to make the overall scope more consistent and easier to write.

| New Prefix | Original Prefix | Source Plugin | | ---------- | ---------------------- | ----------------------------------------------------------------------------------------------------- | | import/* | import-lite/* | eslint-plugin-import-lite | | nextjs/* | @next/next | @next/eslint-plugin-next | | node/* | n/* | eslint-plugin-n | | yaml/* | yml/* | eslint-plugin-yml | | ts/* | @typescript-eslint/* | @typescript-eslint/eslint-plugin | | style/* | @stylistic/* | @stylistic/eslint-plugin | | test/* | vitest/* | @vitest/eslint-plugin | | test/* | no-only-tests/* | eslint-plugin-no-only-tests | | next/* | @next/next | @next/eslint-plugin-next |

When you want to override rules, or disable them inline, you need to update to the new prefix:

-// eslint-disable-next-line @typescript-eslint/consistent-type-definitions
+// eslint-disable-next-line ts/consistent-type-definitions
type foo = { bar: 2 }

Change back to original prefix

If you really want to use the original prefix, you can revert the plugin renaming by:

import { inferno } from '@infernodesign/eslint-config'

export default inferno()
  .renamePlugins( {
    node: 'n',
    ts: '@typescript-eslint',
    yaml: 'yml'
    // ...
  } )

Rules Overrides

Certain rules would only be enabled in specific files, for example, ts/* rules would only be enabled in .ts files and vue/* rules would only be enabled in .vue files. If you want to override the rules, you need to specify the file extension:

// eslint.config.js
import { inferno } from '@infernodesign/eslint-config'

export default inferno(
  {
    typescript: true,
    vue: true
  },
  {
    // Remember to specify the file glob here, otherwise it might cause the vue plugin to handle non-vue files
    files: [ '**/*.vue' ],
    rules: {
      'vue/operator-linebreak': [ 'error', 'before' ],
    },
  },
  {
    // Without `files`, they are general rules for all files
    rules: {
      'style/semi': [ 'error', 'never' ],
    },
  }
)

We also provided the overrides options in each integration to make it easier:

// eslint.config.js
import { inferno } from '@infernodesign/eslint-config'

export default inferno( {
  typescript: {
    overrides: {
      'ts/consistent-type-definitions': [ 'error', 'interface' ],
    },
  },
  vue: {
    overrides: {
      'vue/operator-linebreak': [ 'error', 'before' ],
    },
  },
  yaml: {
    overrides: {
      // ...
    },
  },
} )

Config Composer

Since v2.10.0, the factory function inferno() returns a FlatConfigComposer object from eslint-flat-config-utils where you can chain the methods to compose the config even more flexibly.

// eslint.config.js
import { inferno } from '@infernodesign/eslint-config'

export default inferno()
  .prepend(
    // some configs before the main config
  )
  // overrides any named configs
  .override(
    'antfu/stylistic/rules',
    {
      rules: {
        'style/generator-star-spacing': [ 'error', { after: true, before: false } ],
      }
    }
  )
  // rename plugin prefixes
  .renamePlugins( {
    'old-prefix': 'new-prefix',
    // ...
  } )
// ...

Vue

Vue support is detected automatically by checking if vue is installed in your project. You can also explicitly enable/disable it:

// eslint.config.js
import { inferno } from '@infernodesign/eslint-config'

export default inferno( {
  vue: true
} )

Vue 2

We have limited support for Vue 2 (as it's already reached EOL). If you are still using Vue 2, you can configure it manually by setting vueVersion to 2:

// eslint.config.js
import { inferno } from '@infernodesign/eslint-config'

export default inferno( {
  vue: {
    vueVersion: 2
  },
} )

As it's in maintenance mode, we only accept bug fixes for Vue 2. It might also be removed in the future when eslint-plugin-vue drops support for Vue 2. We recommend upgrading to Vue 3 if possible.

Vue Accessibility

To enable Vue accessibility support, you need to explicitly turn it on:

// eslint.config.js
import { inferno } from '@infernodesign/eslint-config'

export default inferno( {
  vue: {
    a11y: true
  },
} )

Running npx eslint should prompt you to install the required dependencies, otherwise, you can install them manually:

npm i -D eslint-plugin-vuejs-accessibility

Optional Configs

We provide some optional configs for specific use cases, that we don't include their dependencies by default.

Formatters

Use external formatters to format files that ESLint cannot handle yet (.css, .html, etc). Powered by eslint-plugin-format.

// eslint.config.js
import { inferno } from '@infernodesign/eslint-config'

export default inferno( {
  formatters: {
    /**
     * Format CSS, LESS, SCSS files, also the `<style>` blocks in Vue
     * By default uses Prettier
     */
    css: true,
    /**
     * Format HTML files
     * By default uses Prettier
     */
    html: true,
    /**
     * Format Markdown files
     * Supports Prettier and dprint
     * By default uses Prettier
     */
    markdown: 'prettier'
  }
} )

Running npx eslint should prompt you to install the required dependencies, otherwise, you can install them manually:

npm i -D eslint-plugin-format

React

To enable React support, you need to explicitly turn it on:

// eslint.config.js
import { inferno } from '@infernodesign/eslint-config'

export default inferno( {
  react: true,
} )

Running npx eslint should prompt you to install the required dependencies, otherwise, you can install them manually:

npm i -D @eslint-react/eslint-plugin eslint-plugin-react-hooks eslint-plugin-react-refresh

Next.js

To enable Next.js support, you need to explicitly turn it on:

// eslint.config.js
import { inferno } from '@infernodesign/eslint-config'

export default inferno( {
  nextjs: true,
} )

Running npx eslint should prompt you to install the required dependencies, otherwise, you can install them manually:

npm i -D @next/eslint-plugin-next

Storybook

To enable storybook support, you need to explicitly turn it on:

// eslint.config.js
import { inferno } from '@infernodesign/eslint-config'

export default inferno( {
  storybook: true,
} )

Running npx eslint should prompt you to install the required dependencies, otherwise, you can install them manually:

npm i -D eslint-plugin-storybook

Svelte

To enable svelte support, you need to explicitly turn it on:

// eslint.config.js
import { inferno } from '@infernodesign/eslint-config'

export default inferno( {
  svelte: true,
} )

Running npx eslint should prompt you to install the required dependencies, otherwise, you can install them manually:

npm i -D eslint-plugin-svelte

Astro

To enable astro support, you need to explicitly turn it on:

// eslint.config.js
import { inferno } from '@infernodesign/eslint-config'

export default inferno( {
  astro: true,
} )

Running npx eslint should prompt you to install the required dependencies, otherwise, you can install them manually:

npm i -D eslint-plugin-astro

Solid

To enable Solid support, you need to explicitly turn it on:

// eslint.config.js
import { inferno } from '@infernodesign/eslint-config'

export default inferno( {
  solid: true,
} )

Running npx eslint should prompt you to install the required dependencies, otherwise, you can install them manually:

npm i -D eslint-plugin-solid

UnoCSS

To enable UnoCSS support, you need to explicitly turn it on:

// eslint.config.js
import { inferno } from '@infernodesign/eslint-config'

export default inferno( {
  unocss: true,
} )

Running npx eslint should prompt you to install the required dependencies, otherwise, you can install them manually:

npm i -D @unocss/eslint-plugin

Optional Rules

This config also provides some optional plugins/rules for extended usage.

command

Powered by eslint-plugin-command. It is not a typical rule for linting, but an on-demand micro-codemod tool that triggers by specific comments.

For a few triggers, for example:

• /// to-function - converts an arrow function to a normal function
• /// to-arrow - converts a normal function to an arrow function
• /// to-for-each - converts a for-in/for-of loop to .forEach()
• /// to-for-of - converts a .forEach() to a for-of loop
• /// keep-sorted - sorts an object/array/interface
• ... etc. - refer to the documentation

You can add the trigger comment one line above the code you want to transform, for example (note the triple slash):

/// to-function
const foo = async (msg: string): void => {
  console.log(msg)
}

Will be transformed to this when you hit save with your editor or run eslint --fix:

async function foo( msg: string ): void {
  console.log( msg )
}

The command comments are usually one-off and will be removed along with the transformation.

Type Aware Rules

You can optionally enable the type aware rules by passing the options object to the typescript config:

// eslint.config.js
import { inferno } from '@infernodesign/eslint-config'

export default inferno( {
  typescript: {
    tsconfigPath: 'tsconfig.json',
  },
} )

Editor Specific Disables

Auto-fixing for the following rules are disabled when ESLint is running in a code editor:

• prefer-const
• test/no-only-tests
• unused-imports/no-unused-imports

Since v3.16.0, they are no longer disabled, but made non-fixable using this helper.

This is to prevent unused imports from getting removed by the editor during refactoring to get a better developer experience. Those rules will be applied when you run ESLint in the terminal or Lint Staged. If you don't want this behavior, you can disable them:

// eslint.config.js
import { inferno } from '@infernodesign/eslint-config'

export default inferno( {
  isInEditor: false
} )

Lint Staged

If you want to apply lint and auto-fix before every commit, you can add the following to your package.json:

{
  "simple-git-hooks": {
    "pre-commit": "pnpm lint-staged"
  },
  "lint-staged": {
    "*": "eslint --fix"
  }
}

and then

npm i -D lint-staged simple-git-hooks

# to activate the hooks
npx simple-git-hooks

View what rules are enabled

I built a visual tool to help you view what rules are enabled in your project and apply them to what files, @eslint/config-inspector

Go to your project root that contains eslint.config.mjs and run:

npx @eslint/config-inspector

Versioning Policy

This project follows Semantic Versioning for releases. However, since this is just a config and involves opinions and many moving parts, we don't treat rules changes as breaking changes.

Changes Considered as Breaking Changes

• Node.js version requirement changes
• Huge refactors that might break the config
• Plugins made major changes that might break the config
• Changes that might affect most of the codebases

Changes Considered as Non-breaking Changes

• Enable/disable rules and plugins (that might become stricter)
• Rules options changes
• Version bumps of dependencies

FAQ

How to format CSS?

You can opt-in to the formatters feature to format your CSS. Note that it's only doing formatting, but not linting. If you want proper linting support, give stylelint a try.

Top-level Function Style, etc

If you want to disable the opinionated rules, you can disable them with:

import { inferno } from '@infernodesign/eslint-config'

export default inferno( {
  lessOpinionated: true
} )

License

Licensed under the MIT License.

Credits

• Orignally forked from Antfu's eslint-config