Fix session history order when sidebar refresh merges stale server timestamps.

Keep the newer updated_at and max message_count during session list merges so local touchSession updates are not overwritten by lagging Goose summaries.

Co-authored-by: Cursor <cursoragent@cursor.com>

sessions-utils.test.mjs

@@ -0,0 +1,62 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+
+// Keep in sync with src/utils/sessions.ts merge rules for regression coverage.
+function pickNewerIsoTimestamp(left, right) {
+  const leftTime = Date.parse(left ?? '');
+  const rightTime = Date.parse(right ?? '');
+  const leftValid = Number.isFinite(leftTime);
+  const rightValid = Number.isFinite(rightTime);
+  if (!leftValid && !rightValid) return left ?? right;
+  if (!leftValid) return right;
+  if (!rightValid) return left;
+  return leftTime >= rightTime ? left : right;
+}
+
+function mergeSessionRecord(existing, incoming) {
+  if (!existing) return incoming;
+  const merged = { ...existing, ...incoming, id: incoming.id };
+  return {
+    ...merged,
+    updated_at: pickNewerIsoTimestamp(existing.updated_at, incoming.updated_at),
+    message_count: Math.max(Number(existing.message_count ?? 0), Number(incoming.message_count ?? 0)),
+  };
+}
+
+test('mergeSessionRecord keeps the newer updated_at when refreshing stale server summaries', () => {
+  const merged = mergeSessionRecord(
+    {
+      id: 'sess-1',
+      name: 'New Chat',
+      message_count: 4,
+      updated_at: '2026-09-02T14:48:00.000Z',
+    },
+    {
+      id: 'sess-1',
+      name: 'New Chat',
+      message_count: 3,
+      updated_at: '2026-09-02T14:40:00.000Z',
+    },
+  );
+  assert.equal(merged.updated_at, '2026-09-02T14:48:00.000Z');
+  assert.equal(merged.message_count, 4);
+});
+
+test('mergeSessionRecord adopts newer server timestamps when local cache is older', () => {
+  const merged = mergeSessionRecord(
+    {
+      id: 'sess-2',
+      name: 'New Chat',
+      message_count: 2,
+      updated_at: '2026-09-02T14:30:00.000Z',
+    },
+    {
+      id: 'sess-2',
+      name: 'New Chat',
+      message_count: 5,
+      updated_at: '2026-09-02T14:48:00.000Z',
+    },
+  );
+  assert.equal(merged.updated_at, '2026-09-02T14:48:00.000Z');
+  assert.equal(merged.message_count, 5);
+});

src/hooks/useTKMindChat.ts

@@ -88,6 +88,7 @@ import {
   appendSessionLists,
   prependUnique,
   shouldShowNewChatTitle,
+  sortAndTrim,
   toSessionSummary,
   touchSession,
 } from '../utils/sessions';
@@ -750,7 +751,9 @@ export function useTKMindChat(
           offset: 0,
           query: options?.query ?? sessionSearchQueryRef.current,
         });
-        const merged = options?.preserveExisting ? appendSessionLists(sessionsRef.current, items) : items;
+        const merged = options?.preserveExisting
+          ? appendSessionLists(sessionsRef.current, items)
+          : sortAndTrim(items);
         const nextOffset = Number(page.offset ?? 0) + items.length;
         const total = Math.max(Number(page.total ?? merged.length), merged.length);
         sessionsOffsetRef.current = options?.preserveExisting

src/utils/sessions.ts

@@ -43,6 +43,17 @@ export function toSessionSummary(session: Session | SessionSummary): SessionSumm
   };
 }
 
+function pickNewerIsoTimestamp(left?: string, right?: string): string | undefined {
+  const leftTime = Date.parse(left ?? '');
+  const rightTime = Date.parse(right ?? '');
+  const leftValid = Number.isFinite(leftTime);
+  const rightValid = Number.isFinite(rightTime);
+  if (!leftValid && !rightValid) return left ?? right;
+  if (!leftValid) return right;
+  if (!rightValid) return left;
+  return leftTime >= rightTime ? left : right;
+}
+
 export function mergeSessionRecord(
   existing: SessionSummary | undefined,
   incoming: SessionSummary,
@@ -51,15 +62,21 @@ export function mergeSessionRecord(
 
   const keepExistingTitle =
     hasMeaningfulSessionTitle(existing) && !hasMeaningfulSessionTitle(incoming);
-  if (!keepExistingTitle) return { ...existing, ...incoming, id: incoming.id };
+  const merged = keepExistingTitle
+    ? {
+        ...existing,
+        ...incoming,
+        id: incoming.id,
+        name: existing.name,
+        user_set_name: existing.user_set_name,
+        recipe: existing.recipe ?? incoming.recipe,
+      }
+    : { ...existing, ...incoming, id: incoming.id };
 
   return {
-    ...existing,
-    ...incoming,
-    id: incoming.id,
-    name: existing.name,
-    user_set_name: existing.user_set_name,
-    recipe: existing.recipe ?? incoming.recipe,
+    ...merged,
+    updated_at: pickNewerIsoTimestamp(existing.updated_at, incoming.updated_at),
+    message_count: Math.max(Number(existing.message_count ?? 0), Number(incoming.message_count ?? 0)),
   };
 }