From 523e910f2148d578aa4610810ab1262f59dfb27c Mon Sep 17 00:00:00 2001
From: mastertyko <11311479+mastertyko@users.noreply.github.com>
Date: Thu, 26 Mar 2026 23:57:17 +0100
Subject: [PATCH] fix: remove preferences.md from ROOT_STATE_FILES to prevent
 back-sync overwrite
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preferences.md was in ROOT_STATE_FILES which caused syncWorktreeStateBack()
to overwrite the project root's authoritative copy with the worktree's
stale copy. The forward-sync (main → worktree) is already handled
separately in syncGsdStateToWorktree() as additive-only.

Fixes the failing CI test:
  worktree-preferences-sync.test.ts:107
  '#2684: syncWorktreeStateBack does NOT overwrite project root preferences.md'

Also updates preferences-worktree-sync.test.ts to assert preferences.md
is NOT in ROOT_STATE_FILES (it must be handled separately).
---
 src/resources/extensions/gsd/auto-worktree.ts    |  6 ++++--
 .../gsd/tests/preferences-worktree-sync.test.ts  | 16 ++++++++++++----
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/src/resources/extensions/gsd/auto-worktree.ts b/src/resources/extensions/gsd/auto-worktree.ts
index 0b9d28bda..037bb516f 100644
--- a/src/resources/extensions/gsd/auto-worktree.ts
+++ b/src/resources/extensions/gsd/auto-worktree.ts
@@ -82,8 +82,10 @@ const ROOT_STATE_FILES = [
   "QUEUE.md",
   "completed-units.json",
   "metrics.json",
-  "preferences.md",  // #2684: without this, post_unit_hooks and all preference-driven
-                      // config silently stop working inside worktrees.
+  // NOTE: preferences.md is intentionally NOT in ROOT_STATE_FILES.
+  // Forward-sync (main → worktree) is handled explicitly in syncGsdStateToWorktree().
+  // Back-sync (worktree → main) must NEVER overwrite the project root's copy
+  // because the project root is authoritative for preferences (#2684).
 ] as const;
 
 /**
diff --git a/src/resources/extensions/gsd/tests/preferences-worktree-sync.test.ts b/src/resources/extensions/gsd/tests/preferences-worktree-sync.test.ts
index 776c28e70..04a0fbd0f 100644
--- a/src/resources/extensions/gsd/tests/preferences-worktree-sync.test.ts
+++ b/src/resources/extensions/gsd/tests/preferences-worktree-sync.test.ts
@@ -11,7 +11,7 @@ import { readFileSync, mkdtempSync, mkdirSync, writeFileSync, existsSync, rmSync
 import { join } from "node:path";
 import { tmpdir } from "node:os";
 
-test("#2684: ROOT_STATE_FILES includes preferences.md", () => {
+test("#2684: preferences.md is NOT in ROOT_STATE_FILES (forward-only sync)", () => {
   const srcPath = join(import.meta.dirname, "..", "auto-worktree.ts");
   const src = readFileSync(srcPath, "utf-8");
 
@@ -19,12 +19,20 @@ test("#2684: ROOT_STATE_FILES includes preferences.md", () => {
   assert.ok(constIdx !== -1, "ROOT_STATE_FILES constant exists");
 
   const arrayStart = src.indexOf("[", constIdx);
-  const arrayEnd = src.indexOf("]", arrayStart);
+  const arrayEnd = src.indexOf("] as const", arrayStart);
   const block = src.slice(arrayStart, arrayEnd);
 
+  // preferences.md must NOT be in ROOT_STATE_FILES — it is handled separately
+  // in syncGsdStateToWorktree() (forward-only, additive). Including it in
+  // ROOT_STATE_FILES would cause syncWorktreeStateBack() to overwrite the
+  // authoritative project root copy (#2684).
+  const entries = block.split("\n")
+    .map(l => l.trim())
+    .filter(l => l.startsWith('"') && l.includes(".md"));
+  const hasPrefs = entries.some(l => l.includes("preferences.md"));
   assert.ok(
-    block.includes("preferences.md"),
-    "preferences.md should be in ROOT_STATE_FILES list",
+    !hasPrefs,
+    "preferences.md must NOT be in ROOT_STATE_FILES (back-sync would overwrite root)",
   );
 });