From 95e60269504adc33cbd15aa819192fca3b46767a Mon Sep 17 00:00:00 2001
From: Jeffery <jiantw83@yahoo.com>
Date: Thu, 17 Sep 2026 08:23:26 +0000
Subject: [PATCH] =?UTF-8?q?refactor(lib):=20=E9=96=8B=E5=95=9F=E7=9B=AE?=
 =?UTF-8?q?=E6=A8=99=E5=B0=88=E6=A1=88=20git=20repo=20=E7=9A=84=E9=82=A3?=
 =?UTF-8?q?=E5=B9=BE=E8=A1=8C=E6=94=B6=E9=80=B2=20lib?=
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「路徑不是 repo 就報 NOT_A_GIT_REPO」加上「把 cwd 綁進 runGit」原本在 branch-prep 與
commit-split 各寫一份。錯誤碼要一致，而這件事寫第三遍就該收起來了。
---
 scripts/branch-prep.js | 10 ++--------
 scripts/lib.js         | 16 ++++++++++++++++
 2 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/scripts/branch-prep.js b/scripts/branch-prep.js
index bee193a..398c756 100644
--- a/scripts/branch-prep.js
+++ b/scripts/branch-prep.js
@@ -23,9 +23,7 @@
  *   node scripts/branch-prep.js --source <來源分支> --slug <英文-kebab>
  *                               [--type feat] [--path <目標專案>] [--dry-run]
  */
-import { existsSync } from 'node:fs';
-import { join } from 'node:path';
-import { ScriptError, main, parseFlags, runGit } from './lib.js';
+import { ScriptError, main, openGitRepo, parseFlags } from './lib.js';
 
 /** 需求描述的長度上限。超過就換一個短的說法，不要靠截斷。 */
 const SLUG_MAX = 40;
@@ -43,11 +41,7 @@ main(async () => {
   const source = flags.source;
   const branch = buildBranchName(source, flags.slug, flags.type);
 
-  if (!existsSync(join(path, '.git'))) {
-    throw new ScriptError('NOT_A_GIT_REPO', `${path} 不是 git repo；請用 --path 指向目標專案的根目錄`);
-  }
-
-  const git = (...args) => runGit(args, { cwd: path });
+  const git = openGitRepo(path);
   checkClean(git, path);
 
   const hasOrigin = git('remote').split('\n').includes('origin');
diff --git a/scripts/lib.js b/scripts/lib.js
index 9380f47..dca6f77 100644
--- a/scripts/lib.js
+++ b/scripts/lib.js
@@ -379,6 +379,22 @@ export function runGit(args, { cwd } = {}) {
   }
 }
 
+/**
+ * 開一個目標專案的 git repo，回傳綁在它身上的執行器。
+ *
+ * 碰目標專案 git 的腳本都從這裡進去：路徑不是 repo 時的錯誤碼要一致，
+ * 而「把 cwd 綁進 runGit」這件事寫第三遍就該收起來了。
+ *
+ * @param {string} path 目標專案的根目錄
+ * @returns {(...args: string[]) => string} 綁定 cwd 的 git 執行器
+ */
+export function openGitRepo(path) {
+  if (!existsSync(join(path, '.git'))) {
+    throw new ScriptError('NOT_A_GIT_REPO', `${path} 不是 git repo；請用 --path 指向目標專案的根目錄`);
+  }
+  return (...args) => runGit(args, { cwd: path });
+}
+
 // ── 四層前置檢查 ───────────────────────────────────────────────────
 
 /**