Stacked on feat/rfc-2945-pr-c-2-canvas-chat-history. After that PR
merges, this rebases cleanly onto staging.
PR-C-2 (RFC #2945) migrated canvas's loadMessagesFromDB from /activity
to the typed /chat-history endpoint. The TS-side activity-row mapping
helpers in historyHydration.ts (activityRowToMessages,
ActivityRowForHydration) had exactly one consumer — ChatTab's
loadMessagesFromDB — and PR-C-2 removed that consumer.
Verified before deletion:
- grep across canvas/src for historyHydration / activityRowToMessages /
ActivityRowForHydration: only the file itself and its test.
- canvas/src/components/tabs/chat/index.ts barrel: does NOT
re-export historyHydration symbols. Only message-parser.ts is
re-exported (extractAgentText, extractTextsFromParts,
extractResponseText), which is independent.
- message-parser.ts (the parsers historyHydration.ts wraps) STAYS
because it's still load-bearing for live A2A WebSocket messages
in ChatTab.tsx (line ~795), AgentCommsPanel.tsx, and
canvas-events.ts. This delete only targets the row-shape
hydration path, which has fully moved server-side.
- npx tsc --noEmit -p .: clean
- npx vitest run src/components/tabs/: 242/242 green (one fewer
test file than before, 21 vs 22, since historyHydration.test.ts
is gone)
Why now (not after a longer observation window): the parsers in
message-parser.ts that historyHydration.ts depended on are still in
tree, so any unforeseen live-message consumer of activityRowToMessages
would have already failed at PR-C-2 merge time (TypeScript would have
flagged the missing import). Going further by removing the file
itself is purely a dead-code cleanup — no behavioral change.
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