chore: ESLint から Biome へ一元化（#45）

CLAUDE.md

@@ -15,7 +15,8 @@ This repo uses **pnpm** (enforced via a `preinstall` guard; version pinned in
 pnpm install         # honours minimumReleaseAge cooldown (pnpm-workspace.yaml)
 pnpm run all         # typecheck + lint + test + build — run before committing
 pnpm run typecheck   # tsc --noEmit
-pnpm run lint        # eslint .   (lint:fix to autofix)
+pnpm run lint        # biome check . (lint + format + import checks; lint:fix to autofix)
+pnpm run format      # biome format --write .
 pnpm run test        # vitest run
 pnpm run test:watch  # vitest in watch mode
 pnpm run build       # ncc bundles src/main.ts -> dist/index.js

TODO.md

@@ -50,7 +50,6 @@
 |---|---|---|---|---|
 | [#39](https://github.com/yk-lab/setup-task/issues/39) | `[enhancement]` ジョブサマリに導入結果を出力（NFR-5） | `P3: low` | `enhancement` |
 | [#44](https://github.com/yk-lab/setup-task/issues/44) | `[enhancement]` フォールバックソースをサポート（FR-11） | `P3: low` | `enhancement` |
-| [#45](https://github.com/yk-lab/setup-task/issues/45) | `[chore]` Biome 導入を評価 | `P3: low` | `chore` |
 
 ### 未 Issue 化
 
@@ -81,3 +80,4 @@ v1.0.0 実装中に作成・解決済みの Issue（参考）。
 | [#56](https://github.com/yk-lab/setup-task/issues/56) | `[security]` 取得ボディにサイズ上限/タイムアウトを設ける | #61 |
 | [#41](https://github.com/yk-lab/setup-task/issues/41) | `[test]` platform.test.ts を §9 全 os/arch 組合せに拡張 | #62 |
 | [#23](https://github.com/yk-lab/setup-task/issues/23) | `[ci]` ワークフロー静的解析（actionlint / zizmor）を CI に追加 | #68 |
+| [#45](https://github.com/yk-lab/setup-task/issues/45) | `[chore]` Biome 導入を評価 → 一元化採用 | #70 |

biome.json

@@ -0,0 +1,39 @@
+{
+  "$schema": "https://biomejs.dev/schemas/2.5.2/schema.json",
+  "vcs": {
+    "enabled": true,
+    "clientKind": "git",
+    "useIgnoreFile": true
+  },
+  "files": {
+    "includes": ["**", "!**/dist", "!**/coverage"]
+  },
+  "formatter": {
+    "enabled": true,
+    "indentStyle": "space",
+    "indentWidth": 2,
+    "lineWidth": 100
+  },
+  "linter": {
+    "enabled": true,
+    "rules": {
+      "preset": "recommended",
+      "suspicious": {
+        "noExplicitAny": "error"
+      }
+    }
+  },
+  "javascript": {
+    "formatter": {
+      "quoteStyle": "single"
+    }
+  },
+  "assist": {
+    "enabled": true,
+    "actions": {
+      "source": {
+        "organizeImports": "on"
+      }
+    }
+  }
+}

package.json

@@ -14,8 +14,9 @@
     "test": "vitest run",
     "test:coverage": "vitest run --coverage",
     "test:watch": "vitest",
-    "lint": "eslint .",
-    "lint:fix": "eslint . --fix",
+    "lint": "biome check .",
+    "format": "biome format --write .",
+    "lint:fix": "biome check --write .",
     "all": "pnpm run typecheck && pnpm run lint && pnpm run test && pnpm run build"
   },
   "license": "MIT",
@@ -26,14 +27,12 @@
     "undici": "^6.27.0"
   },
   "devDependencies": {
-    "@eslint/js": "^10.0.1",
+    "@biomejs/biome": "2.5.2",
     "@types/node": "^24.13.2",
     "@types/semver": "^7.5.8",
     "@vercel/ncc": "^0.44.0",
     "@vitest/coverage-v8": "^4.1.9",
-    "eslint": "^10.5.0",
     "typescript": "^6.0.3",
-    "typescript-eslint": "^8.20.0",
     "vitest": "^4.1.9"
   },
   "packageManager": "pnpm@11.8.0+sha512.c1f5e7c4cb241c8f174b743851d82f42b802324afc8b0f116b96adb15aa06664948dde36960a3ba1079ba5b4b29dd0140135b94b5b5f5263592249d68e555f26"