chore!: drop support for Node.js 20

Node.js 20 reached end-of-life on 2026-04-30.

- Require Node.js 22 or later in `engines`
- Pin Volta and `.nvmrc` to Node.js 22.22.2
- Bump `@types/node` to ^22.20.4
- Remove Node.js 20 from the CI test matrix
- Update README, CONTRIBUTING, AGENTS and website docs

BREAKING CHANGE: HTMLHint now requires Node.js 22 or later.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: coliff

.github/CONTRIBUTING.md

@@ -13,7 +13,7 @@ We welcome any type of contribution, not only code. You can help with
 
 ## Development setup
 
-Use Node.js 20 or later (the repo pins a version with [Volta](https://volta.sh/) in `package.json`).
+Use Node.js 22 or later (the repo pins a version with [Volta](https://volta.sh/) in `package.json`).
 
 ## Submitting code
 

.github/workflows/test.yml

@@ -43,7 +43,6 @@ jobs:
       fail-fast: false
       matrix:
         node:
-          - 20
           - 22
           - 24
           - 26

.nvmrc

@@ -1 +1 @@
-v20.20.1
+v22.22.2

AGENTS.md

@@ -10,7 +10,7 @@
 - All code should be formatted with Prettier.
 - Use ESLint to check for JavaScript errors.
 - Rollup is used for building the project.
-- Node.js 20 or newer is required; Volta pins the repo to Node 20 LTS in `package.json`.
+- Node.js 22 or newer is required; Volta pins the repo to Node 22 LTS in `package.json`.
 - Core code is in TypeScript.
 - All new rules for HTMLHint should be placed in the rules directory.
 - Tests for new rules should be added in rules and follow the naming pattern `<rule-name>.spec.js`.

README.md

@@ -38,7 +38,7 @@
 
 ## 📟 Installation and Usage
 
-HTMLHint requires [Node.js](https://nodejs.org/) 20 or later.
+HTMLHint requires [Node.js](https://nodejs.org/) 22 or later.
 
 There are two ways to install HTMLHint: globally and locally.
 

package-lock.json

@@ -71,7 +71,7 @@
     "@rollup/plugin-terser": "^1.0.0",
     "@types/async": "^3.2.25",
     "@types/is-glob": "4.0.4",
-    "@types/node": "^20.19.39",
+    "@types/node": "^22.20.4",
     "@types/xml": "^1.0.11",
     "@typescript-eslint/eslint-plugin": "^8.58.2",
     "@typescript-eslint/parser": "^8.58.2",
@@ -86,9 +86,9 @@
     "typescript": "^6.0.3"
   },
   "engines": {
-    "node": ">=20"
+    "node": ">=22"
   },
   "volta": {
-    "node": "20.20.1"
+    "node": "22.22.2"
   }
 }

package.json

@@ -5,7 +5,7 @@ description: How to set up HTMLHint in your project by adding it as a dev depend
 
 import { Tabs, TabItem } from '@astrojs/starlight/components';
 
-HTMLHint requires Node.js 20 or later.
+HTMLHint requires Node.js 22 or later.
 
 1\. Use npm or yarn to install HTMLHint: