mirror of
https://github.com/coder/coder.git
synced 2026-09-24 15:04:27 +08:00
Kyle Carberry
741af057dc
Adds cursor-based pagination to the chat messages endpoint. ## Backend - New `GetChatMessagesByChatIDPaginated` SQL query: returns messages in `id DESC` order with a `before_id` keyset cursor and configurable `limit` - Handler parses `?before_id=N&limit=N` query params, uses the `LIMIT N+1` trick to set `has_more` without a separate COUNT query - Queued messages only returned on the first page (no cursor) since they're always the most recent - SDK client updated with `ChatMessagesPaginationOptions` - Fully backward compatible: omitting params returns the 50 newest messages ## Frontend - Switches `getChatMessages` from `useQuery` to `useInfiniteQuery` with cursor chaining via `getNextPageParam` - Pages flattened and sorted by `id` ascending for chronological display - `MessagesPaginationSentinel` component uses `IntersectionObserver` (200px rootMargin prefetch) inside the existing `flex-col-reverse` scroll container - `flex-col-reverse` handles scroll anchoring natively when older messages are prepended — no manual `scrollTop` adjustment needed (same pattern as coder/blink) ## Why cursor-based instead of offset/limit Offset-based pagination breaks when new messages arrive while paginating backward (offsets shift, causing duplicates or missed messages). The `before_id` cursor is stable regardless of inserts — each page is deterministic.