ESLint JSON Language Plugin

Overview

This package contains a plugin that allows you to natively lint JSON and JSONC files using ESLint.

Important: This plugin requires ESLint v9.6.0 or higher and you must be using the new configuration system.

Installation

For Node.js and compatible runtimes:

npm install @eslint/json -D
# or
yarn add @eslint/json -D
# or
pnpm install @eslint/json -D
# or
bun install @eslint/json -D

For Deno:

deno add @eslint/json

Usage

This package exports two different languages:

• "json/json" is for regular JSON files
• "json/jsonc" is for JSON files that support comments (JSON-C)

Depending on which types of JSON files you'd like to lint, you can set up your eslint.config.js file to include just the files you'd like. Here's an example that lints both JSON and JSON-C files:

import json from "@eslint/json";

export default [
	{
		plugins: {
			json,
		},
	},

	// lint JSON files
	{
		files: ["**/*.json"],
		language: "json/json",
		rules: {
			"json/no-duplicate-keys": "error",
		},
	},

	// lint JSON-C files
	{
		files: ["**/*.jsonc"],
		language: "json/jsonc",
		rules: {
			"json/no-duplicate-keys": "error",
		},
	},
];

Recommended Configuration

To use the recommended configuration for this plugin, specify your matching files and then use the json.configs.recommended object, like this:

import json from "@eslint/json";

export default [
	// lint JSON files
	{
		files: ["**/*.json"],
		language: "json/json",
		...json.configs.recommended,
	},

	// lint JSON-C files
	{
		files: ["**/*.jsonc"],
		language: "json/jsonc",
		...json.configs.recommended,
	},
];

Rules

• no-duplicate-keys - warns when there are two keys in an object with the same text.
• no-empty-keys - warns when there is a key in an object that is an empty string or contains only whitespace

License

Apache 2.0