eslint-plugin-n

forked from eslint-plugin-node v11.1.0. as the original repository seems no longer maintained.

Additional ESLint's rules for Node.js

💿 Install & Usage

$ npm install --save-dev eslint eslint-plugin-n

• Requires Node.js >=12.22.0
• Requires ESLint >=7.0.0

Note: It recommends a use of the "engines" field of package.json. The "engines" field is used by n/no-unsupported-features/* rules.

.eslintrc.json (An example)

{
    "extends": ["eslint:recommended", "plugin:n/recommended"],
    "parserOptions": {
        // Only ESLint 6.2.0 and later support ES2020.
        "ecmaVersion": 2020
    },
    "rules": {
        "n/exports-style": ["error", "module.exports"],
        "n/file-extension-in-import": ["error", "always"],
        "n/prefer-global/buffer": ["error", "always"],
        "n/prefer-global/console": ["error", "always"],
        "n/prefer-global/process": ["error", "always"],
        "n/prefer-global/url-search-params": ["error", "always"],
        "n/prefer-global/url": ["error", "always"],
        "n/prefer-promises/dns": "error",
        "n/prefer-promises/fs": "error"
    }
}

package.json (An example)

{
    "name": "your-module",
    "version": "1.0.0",
    "type": "commonjs",
    "engines": {
        "node": ">=8.10.0"
    }
}

📖 Rules

• ⭐️ - the mark of recommended rules.
• ✒️ - the mark of fixable rules.

Possible Errors

Rule ID	Description
n/handle-callback-err	require error handling in callbacks
n/no-callback-literal	ensure Node.js-style error-first callback pattern is followed
n/no-exports-assign	disallow the assignment to exports	⭐️
n/no-extraneous-import	disallow import declarations which import extraneous modules	⭐️
n/no-extraneous-require	disallow require() expressions which import extraneous modules	⭐️
n/no-missing-import	disallow import declarations which import non-existence modules	⭐️
n/no-missing-require	disallow require() expressions which import non-existence modules	⭐️
n/no-new-require	disallow new operators with calls to require
n/no-path-concat	disallow string concatenation with __dirname and __filename
n/no-process-exit	disallow the use of process.exit()
n/no-unpublished-bin	disallow bin files that npm ignores	⭐️
n/no-unpublished-import	disallow import declarations which import private modules	⭐️
n/no-unpublished-require	disallow require() expressions which import private modules	⭐️
n/no-unsupported-features/es-builtins	disallow unsupported ECMAScript built-ins on the specified version	⭐️
n/no-unsupported-features/es-syntax	disallow unsupported ECMAScript syntax on the specified version	⭐️
n/no-unsupported-features/node-builtins	disallow unsupported Node.js built-in APIs on the specified version	⭐️
n/process-exit-as-throw	make process.exit() expressions the same code path as throw	⭐️
n/shebang	suggest correct usage of shebang	⭐️✒️

Best Practices

Rule ID	Description
n/no-deprecated-api	disallow deprecated APIs	⭐️

Stylistic Issues

Rule ID	Description
n/callback-return	require return statements after callbacks
n/exports-style	enforce either module.exports or exports
n/file-extension-in-import	enforce the style of file extensions in import declarations	✒️
n/global-require	require require() calls to be placed at top-level module scope
n/no-mixed-requires	disallow require calls to be mixed with regular variable declarations
n/no-process-env	disallow the use of process.env
n/no-restricted-import	disallow specified modules when loaded by import declarations
n/no-restricted-require	disallow specified modules when loaded by require
n/no-sync	disallow synchronous methods
n/prefer-global/buffer	enforce either Buffer or require("buffer").Buffer
n/prefer-global/console	enforce either console or require("console")
n/prefer-global/process	enforce either process or require("process")
n/prefer-global/text-decoder	enforce either TextDecoder or require("util").TextDecoder
n/prefer-global/text-encoder	enforce either TextEncoder or require("util").TextEncoder
n/prefer-global/url-search-params	enforce either URLSearchParams or require("url").URLSearchParams
n/prefer-global/url	enforce either URL or require("url").URL
n/prefer-promises/dns	enforce require("dns").promises
n/prefer-promises/fs	enforce require("fs").promises

Deprecated rules

These rules have been deprecated in accordance with the deprecation policy, and replaced by newer rules:

Rule ID	Replaced by
n/no-hide-core-modules	(nothing)
n/no-unsupported-features	n/no-unsupported-features/es-syntax and n/no-unsupported-features/es-builtins

🔧 Configs

This plugin provides three configs:

• plugin:n/recommended considers both CommonJS and ES Modules. If "type":"module" field existed in package.json then it considers files as ES Modules. Otherwise it considers files as CommonJS. In addition, it considers *.mjs files as ES Modules and *.cjs files as CommonJS.
• plugin:n/recommended-module considers all files as ES Modules.
• plugin:n/recommended-script considers all files as CommonJS.

Those preset config:

• enable no-process-exit rule because the official document does not recommend a use of process.exit().
• enable plugin rules which are given ⭐ in the above table.
• add {ecmaVersion: 2019} and etc into parserOptions.
• add proper globals into globals.
• add this plugin into plugins.

👫 FAQ

• Q: The no-missing-import / no-missing-require rules don't work with nested folders in SublimeLinter-eslint
• A: See context.getFilename() in rule returns relative path in the SublimeLinter-eslint FAQ.

🚥 Semantic Versioning Policy

eslint-plugin-n follows semantic versioning and ESLint's Semantic Versioning Policy.

• Patch release (intended to not break your lint build)
  • A bug fix in a rule that results in it reporting fewer errors.
  • Improvements to documentation.
  • Non-user-facing changes such as refactoring code, adding, deleting, or modifying tests, and increasing test coverage.
  • Re-releasing after a failed release (i.e., publishing a release that doesn't work for anyone).
• Minor release (might break your lint build)
  • A bug fix in a rule that results in it reporting more errors.
  • A new rule is created.
  • A new option to an existing rule is created.
  • An existing rule is deprecated.
• Major release (likely to break your lint build)
  • A support for old Node version is dropped.
  • A support for old ESLint version is dropped.
  • An existing rule is changed in it reporting more errors.
  • An existing rule is removed.
  • An existing option of a rule is removed.
  • An existing config is updated.

📰 Changelog

• GitHub Releases

❤️ Contributing

Welcome contributing!

Please use GitHub's Issues/PRs.

Development Tools

• npm test runs tests and measures coverage.
• npm run coverage shows the coverage result of npm test command.
• npm run clean removes the coverage result of npm test command.