grunt-eslint-config

Loads .eslintrc.js or .eslintignore for being used as the options of grunt-eslint. Helps keeping the configuration at a single place.

See grunt-eslintignore for reusing just eslintignore.

How It Works

Let's say that you let all JavaScript files in your project checked as simply as possible by eslint '**/*.js'. You'll use .eslintrc.js or .eslintignore to exclude generated files and build tools. This setup allows using IDE extensions with eslint. However, if you use grunt for building your project, you'll find that grunt-eslint doesn't use ignore patterns from .eslintrc.js or .eslintignore. You'd have to duplicate the ignored patterns in the Gruntfile, when specifying the file patterns to check. You'll be able to reuse .eslintrc.js or .eslintignore , when configuring the eslint task:

const { readEslintConfigFileSync } = require('grunt-eslint-config')

module.exports = grunt => {
  grunt.initConfig({
    eslint: readEslintConfigFileSync()
  })

  grunt.loadNpmTasks('grunt-eslint')
  grunt.registerTask('default', ['eslint'])
}

The contents of .eslintrc.js, for example:

module.exports = {
  extends: ['eslint:recommended'],
  parserOptions: { ecmaVersion: 'latest' },
  env: { node: true }
}

The contents of .eslintignore, for example:

dist/
node_modules/

The options returned by readEslintConfigFileSync are ready to be used for grunt-eslint, for example:

{
  "options": { "overrideConfigFile": ".eslintrc.js" },
  "validate": [
    "**/*.{js,cjs,mjs}",
    "!dist/**/*",
    "!node_modules/**/*"
  ]
}

Alternatively, you can set the ignore patterns to the ignorePatterns property in .eslintrc.js instead of supplying eslintignore.

Installation

This module can be installed in your project using NPM, PNPM or Yarn. Make sure, that you use Node.js version 16 or newer.

$ npm i grunt grunt-eslint@^24 grunt-eslint-config
$ pnpm i grunt grunt-eslint@^24 grunt-eslint-config
$ yarn add grunt grunt-eslint@^24 grunt-eslint-config

Files .eslintignore and the traditional .eslintrc.js were deprecated in eslint 9. If you use them, you probably pin eslint to ^8 and grunt-eslint to ^24.

API

interface ReadEslintConfigOptions {
  // Override the default configuration file name (`.eslintrc.{js,cjs,mjs}`).
  configFileName?: string

  // Override the default pattern for validating scripts (`['**/*.{js,cjs,mjs}']`).
  scriptFiles?: string[]

  // Override the default file name (`.eslintignore`).
  ignoreFileName?: string

  // Override the default current working directory (returned by `process.cwd()`).
  currentWorkingDir?: string

  // The root directory of the current project. It's the directory with `package.json`,
  // where `.eslintignore` is expected. It can be an absolute path or a path relative
  // to `currentWorkingDir`.
  //
  // If this property isn't set, the project directory will be looked by traversing
  // the current working directory and its ancestors until `package.json` is found.
  // The check for `package.json` and going up wil be repeated on `maxDepthToRoot` times.
  projectRootDir?: string

  // The root directory of the current project. It's the directory with `package.json`,
  // where `.eslintignore` is expected. It can be an absolute path or a path relative
  // to `currentWorkingDir`.
  // 
  // How many times will `package.json` be looked up and if not found,
  // go up to the parent directory. The default value is `10`.
  maxDepthToRoot?: number
}

// An object to be used as options for the grunt task `eslint`.
interface GruntEslintOptions {
  options: { overrideConfigFile: string },
  validate: string[]
}

// Reads the contents of `.eslintrc.{js,cjs,mjs}` and returns an object with options
// for the `grunt-eslint` task. If no config file is found, an error will be thrown.
//
// options: see `ReadEslintConfigOptions`
// returns: see `GruntEslintOptions`
function readEslintConfigFile(options?: ReadEslintConfigOptions): Promise<GruntEslintOptions>

// Reads the contents of `.eslintrc.{js,cjs,mjs}` and returns an object with options
// for the `grunt-eslint` task. If no config file is found, an error will be thrown.
//
// options: see `ReadEslintConfigOptions`
// returns: see `GruntEslintOptions`
function readEslintConfigFileSync(options?: ReadEslintConfigOptions): GruntEslintOptions

Contributing

In lieu of a formal styleguide, take care to maintain the existing coding style. Add unit tests for any new or changed functionality. Lint and test your code using Grunt.

License

Copyright (c) 2024 Ferdinand Prantl

Licensed under the MIT license.