eslint-plugin-json-files

5.1.2 verified Sat Apr 25 auth: no javascript

ESLint plugin and processor for linting JSON files, particularly package.json. Current stable version 5.1.2 requires Node >=20.9 and ESLint >=5. It provides 11 rules covering package.json hygiene: sorting, schema validation, dependency restrictions, engines requirements, and no branch dependencies. Unlike generic JSON linters, it focuses on package.json-specific rules. Supports flat config (eslint.config.js) via processor configuration. Released as needed, maintained by Kelly Selden.

Common errors

error Error: Failed to load plugin 'eslint-plugin-json-files' ↓

cause Plugin not installed or missing peer dependency 'eslint'.

fix

Run 'npm install eslint eslint-plugin-json-files --save-dev'.

error Error: Plugin 'eslint-plugin-json-files' uses processor but no processor was set ↓

cause Processor not configured in flat config.

fix

Add 'processor: 'json-files/json'' to the config object.

error Error: Cannot find module 'eslint-plugin-json-files' ↓

cause CommonJS require failing in ESM-only project.

fix

Use dynamic import: 'import jsonFiles from 'eslint-plugin-json-files';' or set "type": "commonjs".

error Rule 'json-files/sort-package-json' is not configured correctly ↓

cause Rule name missing the 'json-files/' prefix.

fix

Use 'json-files/sort-package-json' instead of 'sort-package-json'.

Warnings

breaking v5 drops support for legacy eslintrc config format; only flat config (eslint.config.js) is supported. ↓

fix Migrate from .eslintrc to eslint.config.js using the flat config format shown in the quickstart.

breaking Node.js >=20.9 required starting from v5. Older Node versions will fail to load the plugin. ↓

fix Upgrade Node.js to 20.9 or later.

gotcha Processor must be explicitly set to 'json-files/json' for JSON file linting; omitting it results in no linting of JSON files. ↓

fix Add processor: 'json-files/json' in the flat config object.

deprecated The rule 'json-files/ensure-repository-directory' is deprecated and will be removed in a future major version. ↓

fix Remove the rule from config or migrate to alternative validation.

gotcha Rules only apply to package.json by default; other JSON files need explicit file matching via config. ↓

fix Add 'files' or 'ignores' in config to target specific JSON files.

Install

npm install eslint-plugin-json-files

yarn add eslint-plugin-json-files

pnpm add eslint-plugin-json-files

Imports

default (plugin object)
```
const jsonFiles = require('eslint-plugin-json-files');
```
CommonJS require is supported. For ESM, use dynamic import or set package type to module with Node >=20.
processor 'json-files/json'
```
processor: 'json-files/json'
```
Processor must be referenced as a string literal in the config.
rules (e.g., 'json-files/sort-package-json')
wrong
```
rules: { 'sort-package-json': 'error' }
```
correct
```
rules: { 'json-files/sort-package-json': 'error' }
```
Rule names must be prefixed with 'json-files/'

Quickstart

Configures eslint-plugin-json-files in flat config with processor and two rules.

// eslint.config.js
const jsonFiles = require('eslint-plugin-json-files');

module.exports = [
  {
    plugins: {
      'json-files': jsonFiles,
    },
    processor: 'json-files/json',
    rules: {
      'json-files/sort-package-json': 'error',
      'json-files/require-license': 'error',
    },
  },
];