useParams hook not updating when URL changes from root path

[yoav0gal]

Bug: useParams hook not updating when URL changes from root path

Issue

When starting a new chat from the root path ('/'), the useParams hook in the sidebar doesn't detect the chat ID even after the URL changes to /chat/[id]. This creates a UI inconsistency where the active chat is not highlighted in the sidebar.

Reproduction Steps

0. Create a user and log-in
1. Start at root path ('/')
2. Begin a new chat
3. Send first message
4. URL changes to /chat/[id]
5. Sidebar fails to highlight the active chat because useParams returns undefined.
6. Sidebar fails to navigate back to root ('/') on the chat deletion.

Technical Details

To my understanding, the issue occurs due to how the chat creation flow works with the useChat hook from Vercel's AI SDK. The URL changes happen without triggering a full route change that useParams would detect.
From my understanding - this might be related to the useSWR, in useChat, but that was 2 deep of a dive for me RN 😆

Workaround

Added a fallback to extract the chat ID from pathname when useParams returns undefined at sidebar-history.tsx:

const pathname = usePathname();
const params = useParams();
const id = params.id ?? pathname.split("/").pop();