kandev/docs/plans/task-prompt-transcript-visibility/task-01-preserve-task-prompt-fallback.md

id, title, status, wave, depends_on, plan, spec

id	title	status	wave	depends_on	plan	spec
01-preserve-task-prompt-fallback	Preserve the task prompt fallback	done	1		plan.md	../../specs/ui/requirements/task-prompt-transcript-visibility.md

Task 01: Preserve the task prompt fallback

Intent

If loaded transcript history has no visible user-authored message, keep the original task prompt visible.

Acceptance

• Agent-only or environment-only visible history keeps the synthetic task description as the first message.
• A visible stored user message suppresses the synthetic task description.
• An empty task description does not create an empty synthetic message.
• The transcript keeps its existing message order after the fallback decision.
• The unit regression fails before the production change and passes after it.

Files likely touched

• apps/web/hooks/use-processed-messages.ts
• apps/web/hooks/use-processed-messages-fallback.test.ts

Steps

1. Add the agent-only regression to apps/web/hooks/use-processed-messages-fallback.test.ts.
2. Run the focused unit test and record the expected failure.
3. Change the fallback condition in use-processed-messages.ts to test for a visible user-authored message.
4. Add the stored-user case and run the focused unit test again.
5. Run the web type check and record all results in this task file.

Verification

cd apps && pnpm --filter @kandev/web test -- hooks/use-processed-messages.test.ts
cd apps && pnpm --filter @kandev/web test -- hooks/use-processed-messages-fallback.test.ts
cd apps/web && pnpm run typecheck

Dependencies

None.

Parallelism

Sequential. Task 03 validates this condition with the complete browser flow.

Inputs

• Spec scenarios in docs/specs/ui/requirements/task-prompt-transcript-visibility.md.
• Root-cause location in apps/web/hooks/use-processed-messages.ts.
• Existing launch-persistence coverage in apps/web/e2e/tests/chat/kandev-system-wrap.spec.ts.

Risks

• Use visibleMessages, not the unfiltered message list.
• Do not use task-description equality to detect a real user prompt. Author type is the stable distinction.
• Do not change backend persistence as part of this task.

Output contract

Report the condition change, tests added, exact commands and results, and any remaining risks. Then mark this task as done and update its plan checkbox.

Results

• Updated useProcessedMessages to keep the synthetic task description when visible history contains no user-authored message, while suppressing it for a visible stored user prompt and preserving the empty-description guard.
• Red: cd apps && pnpm --filter @kandev/web test -- hooks/use-processed-messages.test.ts failed at the agent-only fallback assertion before the production change (1 failed, 51 passed).
• Green: cd apps && pnpm --filter @kandev/web test -- hooks/use-processed-messages-fallback.test.ts passed (3 tests), and the existing processed-message suite remained green.
• Added coverage for agent-only history, stored user history, and an empty task description.
• Exported the synthetic row identity so transcript navigation and scroll anchoring can treat it as display-only, and split fallback visibility from message construction so streaming updates reuse the synthetic message object when its inputs are unchanged.
• Final web typecheck passed with cd apps/web && pnpm run typecheck.