Refresh toolchain: Biome 2, TypeScript 7, native Node test running

.github/workflows/ci.yml

@@ -0,0 +1,35 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+  workflow_dispatch:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        node: ['22', '24', '26']
+    steps:
+      - uses: actions/checkout@v7
+      - uses: actions/setup-node@v7
+        with:
+          node-version: ${{ matrix.node }}
+          cache: npm
+      - run: npm ci
+      - run: npm test
+      - run: npm run build
+
+  check:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v7
+      - uses: actions/setup-node@v7
+        with:
+          node-version-file: .node-version
+          cache: npm
+      - run: npm ci
+      - run: npm run check

.node-version

@@ -0,0 +1 @@
+24

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2025 Taylor Beseda
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

@@ -4,6 +4,7 @@
 
 [![typescript](https://img.shields.io/badge/TypeScript-007ACC?style=flat&logo=typescript&logoColor=white)](https://www.typescriptlang.org/)
 [![npm](https://img.shields.io/npm/v/array-treeify.svg)](https://www.npmjs.com/package/array-treeify)
+[![ci](https://github.com/tbeseda/array-treeify/actions/workflows/ci.yml/badge.svg)](https://github.com/tbeseda/array-treeify/actions/workflows/ci.yml)
 [![license](https://img.shields.io/badge/license-MIT-blue.svg)](https://github.com/tbeseda/array-treeify/blob/main/LICENSE)
 
 ## Overview
@@ -57,6 +58,8 @@ Lumon Industries
 npm install array-treeify
 ```
 
+Zero dependencies, ESM only. Requires Node.js 22 or newer (or any runtime that supports ES modules).
+
 ## Usage
 
 ```typescript
@@ -169,6 +172,19 @@ The `treeify` function accepts arrays with the following structure:
 - `chars`: Custom characters for the tree. Defaults to Unicode box-drawing characters.
 - `plain`: When true, uses plain whitespace characters instead of Unicode box-drawing characters.
 
+## Development
+
+Source lives in `src/` and runs directly on Node.js — the tests are `.ts` files executed by Node's built-in test runner and type stripping, so there's no build step or loader involved in testing. Node.js 22.18 or newer is required to work on the library.
+
+```bash
+npm test          # node --test
+npm run typecheck # tsc, covers src/ including tests
+npm run lint      # biome ci, no writes
+npm run lint:write
+npm run check     # typecheck + lint, what CI runs
+npm run build     # emit dist/ with declarations
+```
+
 ## License
 
 MIT © tbeseda

biome.json

@@ -1,25 +1,23 @@
 {
-  "$schema": "https://biomejs.dev/schemas/1.9.4/schema.json",
+  "$schema": "https://biomejs.dev/schemas/2.5.8/schema.json",
   "vcs": {
-    "enabled": false,
+    "enabled": true,
     "clientKind": "git",
-    "useIgnoreFile": false
+    "useIgnoreFile": true
   },
   "files": {
     "ignoreUnknown": false,
-    "ignore": ["package.json"]
+    "includes": ["**", "!**/package.json", "!dist"]
   },
   "formatter": {
     "enabled": true,
     "indentStyle": "space"
   },
-  "organizeImports": {
-    "enabled": true
-  },
+  "assist": { "actions": { "source": { "organizeImports": "on" } } },
   "linter": {
     "enabled": true,
     "rules": {
-      "recommended": true
+      "preset": "recommended"
     }
   },
   "javascript": {