chore: migrate to Biome and Vitest, bump Node to 26 (#62)

- replace ESLint (airbnb) with Biome (2-space, single quotes, semicolons)
- replace Jest with Vitest (vitest.config.js, globals, __tests__ include)
- remove ESLint/Jest dependencies, add @biomejs/biome and vitest
- standardize CI: push+PR on main, Node 26.x, npm cache
- bump engines.node to >=26.0

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: fey

.eslintignore

@@ -1,25 +1,24 @@
 name: Node CI
 
 on:
-  - push
-  - pull_request
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
 
 jobs:
   build:
     runs-on: ubuntu-latest
 
-    strategy:
-      matrix:
-        node-version: [14.x, 15.x, 16.x, 17.x, 18.x]
-
     steps:
       - uses: actions/checkout@v6
-      - name: Use Node.js ${{ matrix.node-version }}
+      - name: Use Node.js
         uses: actions/setup-node@v6
         with:
-          node-version: ${{ matrix.node-version }}
-      - name: Check node version
-        run: node -v
+          node-version: '26.x'
+          cache: 'npm'
       - name: Install
         run: make install
       - name: Run linter

.eslintrc.yml

@@ -9,7 +9,7 @@ test:
 	npm test -s
 
 lint:
-	npx eslint .
+	npx biome check .
 
 publish:
 	npm publish --access public

.github/workflows/nodeci.yml

@@ -1,13 +1,13 @@
 // @ts-check
 
 import {
-  mkdir,
-  mkfile,
-  isFile,
+  filter,
   isDirectory,
+  isFile,
   map,
+  mkdir,
+  mkfile,
   reduce,
-  filter,
 } from '../index.js';
 
 test('build', () => {
@@ -53,12 +53,7 @@ test('isDirectory', () => {
 
 test('reduce', () => {
   const tree = mkdir('/', [
-    mkdir('eTc', [
-      mkdir('NgiNx'),
-      mkdir('CONSUL', [
-        mkfile('config.json'),
-      ]),
-    ]),
+    mkdir('eTc', [mkdir('NgiNx'), mkdir('CONSUL', [mkfile('config.json')])]),
     mkfile('hOsts'),
   ]);
   const actual = reduce((acc) => acc + 1, tree, 0);
@@ -73,12 +68,7 @@ test('reduce', () => {
 
 test('map', () => {
   const tree = mkdir('/', [
-    mkdir('eTc', [
-      mkdir('NgiNx'),
-      mkdir('CONSUL', [
-        mkfile('config.json'),
-      ]),
-    ]),
+    mkdir('eTc', [mkdir('NgiNx'), mkdir('CONSUL', [mkfile('config.json')])]),
     mkfile('hOsts'),
   ]);
   const actual = map((n) => ({ ...n, name: n.name.toUpperCase() }), tree);
@@ -88,7 +78,10 @@ test('map', () => {
       {
         children: [
           {
-            children: [], meta: {}, name: 'NGINX', type: 'directory',
+            children: [],
+            meta: {},
+            name: 'NGINX',
+            type: 'directory',
           },
           {
             children: [{ meta: {}, name: 'CONFIG.JSON', type: 'file' }],
@@ -114,12 +107,8 @@ test('map', () => {
 test('filter', () => {
   const tree = mkdir('/', [
     mkdir('etc', [
-      mkdir('nginx', [
-        mkdir('conf.d'),
-      ]),
-      mkdir('consul', [
-        mkfile('config.json'),
-      ]),
+      mkdir('nginx', [mkdir('conf.d')]),
+      mkdir('consul', [mkfile('config.json')]),
     ]),
     mkfile('hosts'),
   ]);
@@ -130,12 +119,14 @@ test('filter', () => {
       {
         children: [
           {
-            children: [{
-              children: [],
-              meta: {},
-              name: 'conf.d',
-              type: 'directory',
-            }],
+            children: [
+              {
+                children: [],
+                meta: {},
+                name: 'conf.d',
+                type: 'directory',
+              },
+            ],
             meta: {},
             name: 'nginx',
             type: 'directory',

Makefile

@@ -0,0 +1,36 @@
+{
+  "$schema": "./node_modules/@biomejs/biome/configuration_schema.json",
+  "vcs": {
+    "enabled": true,
+    "clientKind": "git",
+    "useIgnoreFile": true
+  },
+  "files": {
+    "ignoreUnknown": false
+  },
+  "formatter": {
+    "enabled": true,
+    "indentStyle": "space",
+    "indentWidth": 2
+  },
+  "linter": {
+    "enabled": true,
+    "rules": {
+      "recommended": true
+    }
+  },
+  "javascript": {
+    "formatter": {
+      "quoteStyle": "single",
+      "semicolons": "always"
+    }
+  },
+  "assist": {
+    "enabled": true,
+    "actions": {
+      "source": {
+        "organizeImports": "on"
+      }
+    }
+  }
+}

__tests__/test.js

@@ -183,6 +183,11 @@ export const filter = (callbackFn, tree) => {
   }
 
   return isDirectory(tree)
-    ? { ...tree, children: tree.children.map((n) => filter(callbackFn, n)).filter((v) => v) }
+    ? {
+        ...tree,
+        children: tree.children
+          .map((n) => filter(callbackFn, n))
+          .filter((v) => v),
+      }
     : tree;
 };