From cecaa174ce9b52006f580e624f4e5fefcfd4370e Mon Sep 17 00:00:00 2001
From: Ravi Kumar L <upman@users.noreply.github.com>
Date: Tue, 9 Jun 2026 16:24:48 -0400
Subject: [PATCH] =?UTF-8?q?=F0=9F=95=B3=EF=B8=8F=20fix:=20Guard=20Sparse?=
 =?UTF-8?q?=20Content=20Parts=20in=20Message=20Nav=20Preview=20(#13632)?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../components/Chat/Messages/MessageNav.tsx   |  4 ++--
 .../Messages/__tests__/MessageNav.spec.tsx    | 23 +++++++++++++++++++
 2 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/client/src/components/Chat/Messages/MessageNav.tsx b/client/src/components/Chat/Messages/MessageNav.tsx
index 128618b9cd..2a4cd0a57e 100644
--- a/client/src/components/Chat/Messages/MessageNav.tsx
+++ b/client/src/components/Chat/Messages/MessageNav.tsx
@@ -3,8 +3,8 @@ import { ChevronUp, ChevronDown } from 'lucide-react';
 import { ContentTypes } from 'librechat-data-provider';
 import { HoverCard, HoverCardTrigger, HoverCardPortal, HoverCardContent } from '@librechat/client';
 import type { TMessage, TMessageContentParts } from 'librechat-data-provider';
-import { useGetMessagesByConvoId } from '~/data-provider';
 import { useMessagesConversation, useMessagesSubmission } from '~/Providers';
+import { useGetMessagesByConvoId } from '~/data-provider';
 import { useLocalize } from '~/hooks';
 import { cn } from '~/utils';
 
@@ -19,7 +19,7 @@ function extractPreviewFromContent(content?: TMessageContentParts[]): string {
     return '';
   }
   for (const part of content) {
-    if (part.type !== ContentTypes.TEXT) {
+    if (part?.type !== ContentTypes.TEXT) {
       continue;
     }
     const textField = part.text;
diff --git a/client/src/components/Chat/Messages/__tests__/MessageNav.spec.tsx b/client/src/components/Chat/Messages/__tests__/MessageNav.spec.tsx
index 2324c7b0d0..4cc9d4008a 100644
--- a/client/src/components/Chat/Messages/__tests__/MessageNav.spec.tsx
+++ b/client/src/components/Chat/Messages/__tests__/MessageNav.spec.tsx
@@ -9,6 +9,13 @@ type TestMessage = {
   conversationId?: string;
   text?: string;
   isCreatedByUser?: boolean;
+  content?: Array<
+    | {
+        type?: string;
+        text?: string | { value?: string };
+      }
+    | undefined
+  >;
 };
 
 const mockUseGetMessagesByConvoId = jest.fn();
@@ -294,6 +301,22 @@ describe('MessageNav', () => {
       expect(text.endsWith('...')).toBe(true);
       expect(text.length).toBe(83);
     });
+
+    it('skips sparse content entries when deriving preview text', () => {
+      const messages = [
+        buildMessage({
+          messageId: 'a',
+          text: '',
+          isCreatedByUser: true,
+          content: [undefined, { type: 'text', text: 'content-preview' }],
+        }),
+        buildMessage({ messageId: 'b', text: 'bravo' }),
+        buildMessage({ messageId: 'c', text: 'charlie', isCreatedByUser: true }),
+      ];
+      const { container } = renderNav(messages);
+      const preview = container.querySelectorAll('[data-testid="hover-card-content"] p')[0];
+      expect(preview).toHaveTextContent('content-preview');
+    });
   });
 
   describe('accessibility', () => {