@antfu/eslint-config

Auto fix for formatting (aimed to be used standalone without Prettier)
Reasonable defaults, best practices, only one line of config
Designed to work with TypeScript, JSX, Vue, JSON, YAML, Toml, Markdown, etc. Out-of-box.
Opinionated, but very customizable
ESLint Flat config, compose easily!
Optional React, 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+

[!IMPORTANT] Since v1.0.0, this config is rewritten to the new ESLint Flat config, check the release note for more details.

Since v3.0.0, ESLint v9.5.0+ is now required.

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 @antfu/eslint-config@latest

Manual Install

If you prefer to set up manually:

pnpm i -D eslint @antfu/eslint-config

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

// eslint.config.mjs
import antfu from "@antfu/eslint-config"

export default antfu()

Combined with legacy config:

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 antfu from "@antfu/eslint-config"
import { FlatCompat } from "@eslint/eslintrc"

const compat = new FlatCompat()

export default antfu(
  {
    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"
  ]
}

🟩 Neovim Support

Update your configuration to use the following:

local 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 },
}

local lspconfig = require('lspconfig')
-- Enable eslint for all supported languages
lspconfig.eslint.setup(
  {
    filetypes = {
      "javascript",
      "javascriptreact",
      "javascript.jsx",
      "typescript",
      "typescriptreact",
      "typescript.tsx",
      "vue",
      "html",
      "markdown",
      "json",
      "jsonc",
      "yaml",
      "toml",
      "xml",
      "gql",
      "graphql",
      "astro",
      "svelte",
      "css",
      "less",
      "scss",
      "pcss",
      "postcss"
    },
    settings = {
      -- Silent the stylistic rules in you IDE, but still auto fix them
      rulesCustomizations = customizations,
    },
  }
)

Neovim format on save

There's few ways you can achieve format on save in neovim:

nvim-lspconfig has a EslintFixAll command predefined, you can create a autocmd to call this command after saving file.

lspconfig.eslint.setup({
  --- ...
  on_attach = function(client, bufnr)
    vim.api.nvim_create_autocmd("BufWritePre", {
      buffer = bufnr,
      command = "EslintFixAll",
    })
  end,
})

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 antfu from "@antfu/eslint-config"

export default antfu()

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

// eslint.config.js
import antfu from "@antfu/eslint-config"

export default antfu({
// 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,

  // 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 antfu from "@antfu/eslint-config"

export default antfu(
  {
    // 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:

Advanced Example

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,
  node,
  sortPackageJson,
  sortTsconfig,
  stylistic,
  toml,
  typescript,
  unicorn,
  vue,
  yaml,
} from "@antfu/eslint-config"

export default combine(
  ignores(),
  javascript(/* Options */),
  comments(),
  node(),
  jsdoc(),
  imports(),
  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-x/*`	eslint-plugin-import-x
`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

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 }

[!NOTE] About plugin renaming - it is actually rather a dangrous move that might leading to potential naming collisions, pointed out here and here. As this config also very personal and opinionated, I ambitiously position this config as the only "top-level" config per project, that might pivots the taste of how rules are named.

This config cares more about the user-facings DX, and try to ease out the implementation details. For example, users could keep using the semantic import/order without ever knowing the underlying plugin has migrated twice to eslint-plugin-i and then to eslint-plugin-import-x. User are also not forced to migrate to the implicit i/order halfway only because we swapped the implementation to a fork.

That said, it's probably still not a good idea. You might not want to doing this if you are maintaining your own eslint config.

Feel free to open issues if you want to combine this config with some other config presets but faced naming collisions. I am happy to figure out a way to make them work. But at this moment I have no plan to revert the renaming.

Since v2.9.0, this preset will automatically rename the plugins also for your custom configs. You can use the original prefix to override the rules directly.

Change back to original prefix

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

import antfu from "@antfu/eslint-config"

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

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 antfu from "@antfu/eslint-config"

export default antfu(
  {
    vue: true,
    typescript: 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 antfu from "@antfu/eslint-config"

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

Config Composer

Since v2.10.0, the factory function antfu() 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 antfu from "@antfu/eslint-config"

export default antfu()
  .prepend(
    // some configs before the main config
  )
  // overrides any named configs
  .override(
    "antfu/imports",
    {
      rules: {
        "import/order": ["error", { "newlines-between": "always" }],
      }
    }
  )
  // 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 antfu from "@antfu/eslint-config"

export default antfu({
  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 antfu from "@antfu/eslint-config"

export default antfu({
  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.

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 antfu from "@antfu/eslint-config"

export default antfu({
  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"
  }
})