fix(platform): make failed status unconditionally terminal and remove dead code

[Israeltheminer]

Summary

Addresses review feedback from @larryro on #599. The Convex Agent SDK maps stream abort to failed (not aborted) at the UIMessage level via statusFromStreamStatus(), and finishReason never contains cancelled (valid values: stop, length, content-filter, tool-calls, error, other, unknown).

• Fix stuck loading on mid-tool-call failure: failed is now unconditionally terminal — when generation fails during a tool turn, isLoading correctly resolves to false instead of staying stuck forever
• Remove dead aborted status checks: SDK never surfaces aborted as a UIMessage status (maps to failed), so these checks in use-chat-loading-state.ts and use-message-processing.ts were unreachable
• Remove dead finishReason === 'cancelled' check: Not a valid vFinishReason value in the SDK, so this early-return in internal_actions.ts was unreachable
• Remove dead history.toast.titleEmpty i18n key: No longer referenced anywhere after sidebar rename UX changes
• Fix min-h mismatch in sidebar: Edit input used min-h-[1.5rem] (24px) while display span used min-h-[20px] — aligned both to 1.5rem

Test plan

• Updated use-chat-loading-state.test.ts — replaced tool-turn-aware tests with failed unconditionally terminal tests
• Added test: failed mid-tool-call clears isPending
• Lint passes (0 warnings, 0 errors)
• Format passes
• CI checks pass

🤖 Generated with Claude Code

Summary by CodeRabbit

• Bug Fixes

  • Fixed loading state indicator to properly clear when tool calls fail, ensuring accurate feedback during chat operations.
  • Improved handling of failed operations during message processing.

• Style

  • Refined chat title area vertical spacing for better UI consistency.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

Configuration used: Organization UI

Review profile: ASSERTIVE

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between f623b68 and ad2c63a.

📒 Files selected for processing (6)

• services/platform/app/features/chat/components/chat-history-sidebar.tsx
• services/platform/app/features/chat/hooks/__tests__/use-chat-loading-state.test.ts
• services/platform/app/features/chat/hooks/use-chat-loading-state.ts
• services/platform/app/features/chat/hooks/use-message-processing.ts
• services/platform/convex/lib/agent_chat/internal_actions.ts
• services/platform/messages/en.json

💤 Files with no reviewable changes (2)

• services/platform/messages/en.json
• services/platform/convex/lib/agent_chat/internal_actions.ts

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📝 Walkthrough

Walkthrough

This pull request refactors the chat loading state logic and message processing across multiple files. The core changes involve simplifying the loading determination by removing the isUnfinishedToolTurn helper and treating 'failed' status as a terminal condition, alongside removing special handling for 'aborted' status in streaming state management. Related test expectations were updated to reflect the new terminal condition semantics. Additionally, an early return on 'cancelled' finishReason was removed from the agent chat action handler. A UI adjustment changes the chat title span min-height from 20px to 1.5rem, and the localization file removes the "titleEmpty" toast message entry.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Possibly related PRs

• feat(platform): improve chat UX with animation fixes and add-agent button #560: Modifies use-message-processing.ts to change streaming and terminal-status handling, with direct code overlap in the same streaming state management logic.
• feat(platform): refine chat streaming UX and simplify marker parser #511: Updates chat message-processing and loading logic in use-chat-loading-state and related hooks, affecting terminal status determination for loading state.
• fix(platform): prevent chat loading state flicker during tool call transitions #492: Modifies use-message-processing.ts and loading hooks with complementary changes to preserve loading state across streaming and pending transitions.

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 66.67% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately describes the main changes: making failed status unconditionally terminal and removing dead code related to aborted/cancelled status handling across multiple files.

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• Commit unit tests in branch fix/chat-loading-state-failed-status

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[greptile-apps]

Greptile Summary

This PR addresses review feedback from #599 by simplifying loading state management and removing dead code paths. The key insight is that the Convex Agent SDK maps stream abort to failed status (not aborted), which means the previous tool-turn-aware loading logic was unnecessarily complex.

Key changes:

• Made failed status unconditionally terminal in use-chat-loading-state.ts, fixing a bug where failures during tool turns would leave isLoading stuck forever
• Removed unreachable aborted status checks (SDK never surfaces this status at the UIMessage level)
• Removed unreachable finishReason === 'cancelled' check (not a valid vFinishReason value in the SDK)
• Fixed UI inconsistency: aligned min-height between display span and edit input in sidebar
• Removed unused i18n key history.toast.titleEmpty

All changes are well-tested with comprehensive test coverage that verifies the new behavior, including a new test specifically for failed mid-tool-call clearing isPending.

Confidence Score: 5/5

• This PR is safe to merge with no risk
• Clean refactoring that simplifies code while fixing a real bug. All changes are well-tested with comprehensive test coverage. The dead code removal is verified (no remaining references to aborted status or titleEmpty key). The logic simplification is sound and makes the code more maintainable.
• No files require special attention

Important Files Changed

Filename	Overview
services/platform/app/features/chat/hooks/use-chat-loading-state.ts	Simplified loading state logic by removing tool-turn awareness and making failed status unconditionally terminal
services/platform/app/features/chat/hooks/tests/use-chat-loading-state.test.ts	Updated tests to remove tool-turn awareness checks and added test for failed mid-tool-call clearing isPending
services/platform/app/features/chat/hooks/use-message-processing.ts	Removed aborted status check from streaming state cleanup logic
services/platform/convex/lib/agent_chat/internal_actions.ts	Removed unreachable early return for finishReason === 'cancelled'

_{Last reviewed commit: ad2c63a}

[larryro]

lgtm