@radum Eslint config

Personal recommended shareable config for eslint. Started as a rip-off of Anthony's ESLint config preset amazing config but added my own flavour to it. Use it as is or as a foundation for your own config. You can extend or clone and change.

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+

[!NOTE] Since v7.0.0, this config is rewritten to the new ESLint Flat config, check the release note for more details.

Since v8.0.0, ESLint v9.5.0+ is now required.

[!WARNING] Please keep in mind that this is a personal config with a lot opinions. Changes might not always be pleased by everyone and every use cases.

If you are using this config directly, I'd suggest you review the changes everytime you update. Or if you want more control over the rules, always feel free to fork it. Thanks!

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 @radum/eslint-config@latest

Manual Install

If you prefer to set up manually:

pnpm i -D eslint @radum/eslint-config

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

// eslint.config.mjs
import radum from '@radum/eslint-config';

export default radum();

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.

import { FlatCompat } from '@eslint/eslintrc';
// eslint.config.mjs
import radum from '@radum/eslint-config';

const compat = new FlatCompat();

export default radum(
	{
		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 v7.0, we migrated to ESLint Flat config. It provides much better organization and composition.

Normally you only need to import the radum preset:

// eslint.config.js
import radum from '@radum/eslint-config';

export default radum();

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

// eslint.config.js
import radum from '@radum/eslint-config';

export default radum({
// 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 radum factory function also accepts any number of arbitrary custom config overrides:

// eslint.config.js
import radum from '@radum/eslint-config';

export default radum(
	{
		// Configures for radum'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 '@radum/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 dangerous 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.

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 radum from '@radum/eslint-config';

export default radum()
	.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 radum from '@radum/eslint-config';

export default radum(
	{
		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 radum from '@radum/eslint-config';

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

Config Composer

The factory function radum() 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 radum from '@radum/eslint-config';

export default radum()
	.prepend(
		// some configs before the main config
	)
	// overrides any named configs
	.override(
		'radum/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 radum from '@radum/eslint-config';

export default radum({
	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 radum from '@radum/eslint-config';

export default radum({
	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 radum from '@radum/eslint-config';

export default radum({
	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'
	}
});