@ajiu9/eslint-config

Auto fix for formatting (aimed to be used standalone without Prettier)
Reasonable defaults, best practices, only one line of config
ESLint Flat config, compose easily!
Designed to work with TypeScript, Markdown, Vue, YAML, etc.
Style principle: Minimal for reading, stable for diff, consistent
- Sorted imports, dangling commas
- Single quotes, no semi
Respects .gitignore by default
Requires ESLint v9.5.0+-

#Usage

pnpm add -D eslint @ajiu9/eslint-config

Config `.eslintrc`

{
  "extends": "@ajiu9"
}

You don't need .eslintignore normally as it has been provided by the preset.

Add script for package.json

For example:

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

VS Code support (auto fix)

Install VS Code ESLint extension

Add the following settings to your settings.json:

{
  "prettier.enable": false,
  "editor.formatOnSave": false,
  "editor.codeActionsOnSave": {
    "source.fixAll.eslint": true,
    "source.organizeImports": false
  },

  // The following is optional.
  // It's better to put under project setting `.vscode/settings.json`
  // to avoid conflicts with working with different eslint configs
  // that does not support all formats.
  "eslint.validate": [
    "javascript",
    "javascriptreact",
    "typescript",
    "typescriptreact",
    "vue",
    "html",
    "markdown",
    "json",
    "jsonc",
    "yaml"
  ]
}

TypeScript Aware Rules

Type aware rules are enabled when a tsconfig.eslint.json is found in the project root, which will introduce some stricter rules into your project. If you want to enable it while have no tsconfig.eslint.json in the project root, you can change tsconfig name by modifying ESLINT_TSCONFIG env.

// .eslintrc.js
process.env.ESLINT_TSCONFIG = 'tsconfig.json'

module.exports = {
  extends: '@ajiu9'
}

Lint Staged

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

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

and then

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

Customization

Normally you only need to import the ajiu9 preset:

// eslint.config.js
import ajiu9 from '@ajiu9/eslint-config'

export default ajiu9()

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

// eslint.config.js
import ajiu9 from '@ajiu9/eslint-config'

export default ajiu9({
// 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 ajiu9 factory function also accepts any number of arbitrary custom config overrides:

// eslint.config.js
import ajiu9 from '@ajiu9/eslint-config'

export default ajiu9(
  {
    // Configures for ajiu9's config
  },

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

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 ajiu9 from '@ajiu9/eslint-config'

export default ajiu9({
  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 ajiu9 from '@ajiu9/eslint-config'

export default ajiu9({
  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.

Formatters

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

// eslint.config.js
import ajiu9 from '@ajiu9/eslint-config'

export default ajiu9({
  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

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 ajiu9 from '@ajiu9/eslint-config'

export default ajiu9(
  {
    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 ajiu9 from '@ajiu9/eslint-config'

export default ajiu9({
  vue: {
    overrides: {
      'vue/operator-linebreak': ['error', 'before'],
    },
  },
  typescript: {
    overrides: {
      'ts/consistent-type-definitions': ['error', 'interface'],
    },
  },
  yaml: {
    overrides: {
      // ...
    },
  },
})