Closes the 3rd PR #138 review.
Warning fix: the render-phase reconciler only disarms the error-path adoption
fallback when activeChatId actually changes. Pressing 'New chat' while ALREADY
in a new chat keeps activeChatId === null (a no-op atom write), so the reconciler
never fired and a stale armed fallback could adopt the just-failed chat from a
late refetch, yanking the user out of their fresh chat. useChatSession now
returns cancelPendingAdoption(); the window calls it from startNewChat AND
selectChat. (The hook call moved above those callbacks so they can reference it.)
Added a hook test that fails without the explicit disarm, plus a test for the
existing-chat onTurnFinished branch (no adoption + per-chat invalidation).
Cleanups: removed the dead pickNewlyCreatedChatId (the fallback effect uses
newlyAddedChatIds directly with the 0/1/>1 decision inline) and its tests/doc
mention; inlined the two invalidation closures (onTurnFinished is read live by
useChat's onFinish, never in an effect dep array, so memoizing them was needless
ceremony).
Verified: tsc clean, 127 ai-chat tests green; live (z.ai glm-5.2) new chat + 2nd
turn recalled the number in the SAME row (1 chat / 4 messages), no page errors.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Addresses the 2nd PR #138 review (test debt + the Variant-B architecture ask).
The new→persisted chat id lifecycle (mount key, both adoption paths, the
history-load latch, the render-phase reconciler, onTurnFinished) is moved out of
the 768-line window into a new useChatSession hook driven by a pure
threadSessionReducer (reconcile/adopt), so adopt-vs-switch is one explicit
dispatch point and the scattering the review flagged is gone (window: 768→~620).
Tests (the blockers):
- use-chat-session.test.tsx — hook-level locks incl. the #137 regression
(adopts the authoritative streamed id 'A', NOT chats.items[0]='B' — fails on
the old heuristic), the error-path fallback (arm/adopt/ambiguous/add+delete),
the disarm-on-reconcile lock (a fallback armed then switched away must not be
adopted by a late refetch), in-place-adopt-keeps-key vs external-switch-remount,
and the waitingForHistory latch.
- extractServerChatId (reading message.metadata.chatId) and newlyAddedChatIds
extracted as pure helpers with unit tests; threadSessionReducer tested.
Cleanups: single canonical #137 explanation in adopt-chat-id.ts (other sites
reference it); fallback effect computes the set diff once; invalidate callbacks
memoized; redundant invariant tests folded.
Behavior preserved — re-verified live (z.ai glm-5.2): new-chat adopt + 2nd turn
in the same row, no mid-conversation remount, two-tab race leak-free, switch to
an existing chat reseeds full history, reload restores history.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Addresses the PR #138 review.
Blocker 1 — duplicate chat row: a brand-new chat whose first turn errors BEFORE
the SSE 'start' chunk never receives the authoritative chatId, so metadata
adoption can't run; a retry then sent chatId:null and the server inserted a
SECOND chat row, orphaning the first turn. Keep metadata adoption as the primary
path (resolveAdoptedChatId) and add a bounded, unambiguous fallback: on a
new-chat finish with no server id, snapshot the known chat ids and, once the
list refetch lands, adopt the SINGLE newly-appeared id (pickNewlyCreatedChatId).
Zero or >1 new ids (e.g. two tabs racing) → no adoption — no items[0] guessing,
so #137 stays fixed. The wait-for-refetch guard compares set membership (robust
to a concurrent delete), and the diff dedupes so a repeated id from a paginated
list never reads as ambiguous.
Blocker 2 — tests: new adopt-chat-id.test.ts covers both pure helpers (adopt
decision + newly-created-id diff incl. dedupe/reorder); the server
messageMetadata callback is extracted to chatStreamStartMetadata and unit-tested
(start -> {chatId}, otherwise undefined).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
claude code agent 227