eslint-plugin-n

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 as the original repository seems no longer maintained.

Additional ESLint rules for Node.js

🎨 Playground

online-playground

💿 Install & Usage

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

| Version | Supported Node.js | Supported ESLint Version | |---------|-------------------|---------------------------| | 17.x | ^18.18.0 \|\| ^20.9.0 \|\| >=21.1.0 | >=8.23.0 | | 16.x | >=16.0.0 | >=7.0.0 | | 15.x | >=12.22.0 | >=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": {
        "ecmaVersion": 2021
    },
    "rules": {
        "n/exports-style": ["error", "module.exports"]
    }
}

eslint.config.js (requires eslint>=v8.23.0)

const nodePlugin = require("eslint-plugin-n")

module.exports = [
    nodePlugin.configs["flat/recommended-script"],
    {
        rules: {
            "n/exports-style": ["error", "module.exports"]
        }
    }
]

package.json (An example)

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

Configured Node.js version range

The rules get the supported Node.js version range from the following, falling back to the next if unspecified:

1. Rule configuration version
2. ESLint shared setting node.version
3. package.json engines field
4. >=16.0.0

If you omit the engines field, this rule chooses >=16.0.0 as the configured Node.js version since 16 is the maintained lts (see also Node.js Release Working Group).
For Node.js packages, using the engines field is recommended because it's the official way to indicate support:

{
    "name": "your-module",
    "version": "1.0.0",
    "engines": {
        "node": ">=16.0.0"
    }
}

For Shareable Configs or packages with a different development environment (e.g. pre-compiled, web package, etc.), you can configure ESLint with settings.node.version to specify support.

📖 Rules

💼 Configurations enabled in.\ ☑️ Set in the flat/recommended configuration.\ 🟢 Set in the flat/recommended-module configuration.\ ✅ Set in the flat/recommended-script configuration.\ ☑️ Set in the recommended configuration.\ 🟢 Set in the recommended-module configuration.\ ✅ Set in the recommended-script configuration.\ 🔧 Automatically fixable by the --fix CLI option.\ ❌ Deprecated.
| Name                                  | Description | 💼 | 🔧 | ❌ | | :------------------------------------------------------------------------------------------- | :-------------------------------------------------------------------------- | :-------------- | :- | :- | | callback-return | require return statements after callbacks | | | | | exports-style | enforce either module.exports or exports | | 🔧 | | | file-extension-in-import | enforce the style of file extensions in import declarations | | 🔧 | | | global-require | require require() calls to be placed at top-level module scope | | | | | handle-callback-err | require error handling in callbacks | | | | | hashbang | require correct usage of hashbang | ☑️ 🟢 ✅ ☑️ 🟢 ✅ | 🔧 | | | no-callback-literal | enforce Node.js-style error-first callback pattern is followed | | | | | no-deprecated-api | disallow deprecated APIs | ☑️ 🟢 ✅ ☑️ 🟢 ✅ | | | | no-exports-assign | disallow the assignment to exports | ☑️ 🟢 ✅ ☑️ 🟢 ✅ | | | | no-extraneous-import | disallow import declarations which import extraneous modules | ☑️ 🟢 ✅ ☑️ 🟢 ✅ | | | | no-extraneous-require | disallow require() expressions which import extraneous modules | ☑️ 🟢 ✅ ☑️ 🟢 ✅ | | | | no-hide-core-modules | disallow third-party modules which are hiding core modules | | | ❌ | | no-missing-import | disallow import declarations which import non-existence modules | ☑️ 🟢 ✅ ☑️ 🟢 ✅ | | | | no-missing-require | disallow require() expressions which import non-existence modules | ☑️ 🟢 ✅ ☑️ 🟢 ✅ | | | | no-mixed-requires | disallow require calls to be mixed with regular variable declarations | | | | | no-new-require | disallow new operators with calls to require | | | | | no-path-concat | disallow string concatenation with __dirname and __filename | | | | | no-process-env | disallow the use of process.env | | | | | no-process-exit | disallow the use of process.exit() | ☑️ 🟢 ✅ ☑️ 🟢 ✅ | | | | no-restricted-import | disallow specified modules when loaded by import declarations | | | | | no-restricted-require | disallow specified modules when loaded by require | | | | | no-sync | disallow synchronous methods | | | | | no-unpublished-bin | disallow bin files that npm ignores | ☑️ 🟢 ✅ ☑️ 🟢 ✅ | | | | no-unpublished-import | disallow import declarations which import private modules | ☑️ 🟢 ✅ ☑️ 🟢 ✅ | | | | no-unpublished-require | disallow require() expressions which import private modules | ☑️ 🟢 ✅ ☑️ 🟢 ✅ | | | | no-unsupported-features/es-builtins | disallow unsupported ECMAScript built-ins on the specified version | ☑️ 🟢 ✅ ☑️ 🟢 ✅ | | | | no-unsupported-features/es-syntax | disallow unsupported ECMAScript syntax on the specified version | ☑️ 🟢 ✅ ☑️ 🟢 ✅ | | | | no-unsupported-features/node-builtins | disallow unsupported Node.js built-in APIs on the specified version | ☑️ 🟢 ✅ ☑️ 🟢 ✅ | | | | prefer-global/buffer | enforce either Buffer or require("buffer").Buffer | | | | | prefer-global/console | enforce either console or require("console") | | | | | prefer-global/process | enforce either process or require("process") | | | | | prefer-global/text-decoder | enforce either TextDecoder or require("util").TextDecoder | | | | | prefer-global/text-encoder | enforce either TextEncoder or require("util").TextEncoder | | | | | prefer-global/url | enforce either URL or require("url").URL | | | | | prefer-global/url-search-params | enforce either URLSearchParams or require("url").URLSearchParams | | | | | prefer-node-protocol | enforce using the node: protocol when importing Node.js builtin modules. | | 🔧 | | | prefer-promises/dns | enforce require("dns").promises | | | | | prefer-promises/fs | enforce require("fs").promises | | | | | process-exit-as-throw | require that process.exit() expressions use the same code path as throw | ☑️ 🟢 ✅ ☑️ 🟢 ✅ | | | | shebang | require correct usage of hashbang | | 🔧 | ❌ |

🔧 Configs

| | Name | | :- | :------------------------ | | 🟠 | flat/mixed-esm-and-cjs | | ☑️ | flat/recommended | | 🟢 | flat/recommended-module | | ✅ | flat/recommended-script | | ☑️ | recommended | | 🟢 | recommended-module | | ✅ | recommended-script |

About each config:

• 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.
• recommended-module: Considers all files as ES Modules.
• recommended-script: Considers all files as CommonJS.

These preset configs:

• enable no-process-exit rule because the official document does not recommend a use of process.exit().
• enable plugin rules indicated by emojis in the rules table.
• add {ecmaVersion: 2021} 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.

• Q: How to use the flat eslint config with mixed commonjs and es modules?
• A: You can use the new exported flat config flat/mixed-esm-and-cjs, an example:

const nodePlugin = require("eslint-plugin-n");

module.exports = [
  ...nodePlugin.configs["flat/mixed-esm-and-cjs"],
  {
    rules: {
      "n/exports-style": ["error", "module.exports"],
    },
  },
]

🚥 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.
Deprecated rules follow ESLint's deprecation policy.

📰 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.