[graycyrus]

Bug

hydrateRuntimeFromSnapshot in app/src/store/chatRuntimeSlice.ts was fixed in #4886 to only clear pendingWorkflowProposalsByThread on snapshot.lifecycle === 'interrupted' (not 'completed') — a completed snapshot can be this session's own just-settled turn racing against the live path.

The same reducer still unconditionally cleared streamingAssistantByThread[threadId] and rewrote toolTimelineByThread[threadId] for any terminal snapshot, including completed. Concretely, ChatRuntimeProvider's socket-disconnect reconciliation deliberately keeps streamingAssistantByThread set across endInferenceTurn so a partial reply stays visible while the socket reconnects (see the comment at ChatRuntimeProvider.tsx:1403). If a completed fetchAndHydrateTurnState rehydration then lands for that thread, it wiped the just-preserved streaming bubble and replaced the live (richer) tool timeline with the (behind) persisted snapshot — a transient flicker / loss of just-streamed narration, even though the proposal card itself now survives.

Fix

Split the terminal-snapshot block in hydrateRuntimeFromSnapshot:

• inferenceStatusByThread clear and processingByThread assignment still happen unconditionally for both interrupted/completed (unaffected by this bug).
• The streamingAssistantByThread delete + toolTimelineByThread overwrite now only run when snapshot.lifecycle === 'interrupted' (genuine crash — nothing fresher can exist) or there is no live streaming state for the thread (!state.streamingAssistantByThread[threadId]), which covers cold boot / new window so history still hydrates.

This mirrors the interrupted-only invariant already used for the workflow-proposal clear from #4886, keeping the three guards (proposal / streaming lane / tool timeline) consistent.

Tests

Added to app/src/store/chatRuntimeSlice.test.ts (hydrateRuntimeFromSnapshot — streaming/timeline race guard):

• does not wipe a fresher streaming/tool-timeline lane on a completed snapshot
• clears the streaming/tool-timeline lanes on an interrupted snapshot (crash cleanup)
• still hydrates the timeline from a completed snapshot on cold boot (no prior live state)

Test plan

• corepack pnpm typecheck clean
• corepack pnpm lint clean (0 errors; pre-existing unrelated warnings in other files)
• corepack pnpm test --config app/test/vitest.config.ts src/store/chatRuntimeSlice.test.ts — 30/30 passed
• corepack pnpm format — no diff beyond the intended change

Summary by CodeRabbit

• Bug Fixes

  • Improved chat state recovery after reconnection to prevent active streaming responses and tool activity from being overwritten by older completed snapshots.
  • Ensured interrupted conversations are properly cleared and cleaned up.
  • Preserved tool activity history when restoring completed conversations during a cold start.

• Tests

  • Added regression coverage for reconnect races, interrupted sessions, and cold-start restoration.

[coderabbitai]

📝 Walkthrough

Walkthrough

hydrateRuntimeFromSnapshot now avoids overwriting fresher live streaming and tool-timeline state for completed snapshots, while interrupted snapshots still clear those lanes. Tests cover reconnect races, crash cleanup, and cold-boot hydration.

Changes

Runtime snapshot hydration

Layer / File(s)	Summary
Guard terminal snapshot reconciliation app/src/store/chatRuntimeSlice.ts	Completed snapshots preserve existing live streaming and tool-timeline state; interrupted snapshots and snapshots without live streaming retain cleanup and settlement behavior.
Validate hydration race behavior app/src/store/chatRuntimeSlice.test.ts	Tests verify live-state preservation, interrupted cleanup, and cold-boot tool-timeline hydration.

Estimated code review effort: 3 (Moderate) | ~20 minutes

Suggested labels: bug

Suggested reviewers: oxoxdev, senamakel, sanil-23

Poem

I’m a bunny guarding streams in flight,
Keeping fresh live lanes safe and bright.
Completed snapshots wait their turn,
Interrupted paths clean what they burn.
Cold boots bloom with timelines true—
Hop, hop, the race guard’s through!

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly summarizes the main fix: preserving fresh streaming and tool-timeline state during completed snapshot hydration.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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[coderabbitai]

🧹 Nitpick comments (1)

app/src/store/chatRuntimeSlice.ts (1)

1993-2014: 📐 Maintainability & Code Quality | 🔵 Trivial

Add a branch-level chatRuntime.turnState log in this completed/interrupted guard.

fetchAndHydrateTurnState already logs the hydrate attempt, but this reconciliation still has no signal for whether the live stream was preserved or cleared. Log only lifecycle and hasFresherLiveStream so reconnect races stay grep-friendly.

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@app/src/store/chatRuntimeSlice.ts` around lines 1993 - 2014, Add a
branch-level chatRuntime.turnState log within the snapshot lifecycle guard
around hasFresherLiveStream, recording only snapshot.lifecycle and
hasFresherLiveStream. Emit it whether the live stream is preserved or cleared,
without logging snapshot contents or other state.

Source: Coding guidelines

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Nitpick comments:
In `@app/src/store/chatRuntimeSlice.ts`:
- Around line 1993-2014: Add a branch-level chatRuntime.turnState log within the
snapshot lifecycle guard around hasFresherLiveStream, recording only
snapshot.lifecycle and hasFresherLiveStream. Emit it whether the live stream is
preserved or cleared, without logging snapshot contents or other state.

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 932ec7bc-4ebd-4e00-a0b6-747a6eb0a0b7

📥 Commits

Reviewing files that changed from the base of the PR and between 0e86b85 and 049d3e1.

📒 Files selected for processing (2)

• app/src/store/chatRuntimeSlice.test.ts
• app/src/store/chatRuntimeSlice.ts