[Vishal Punjabi (vshalpnjabi)]

Description

Fixes #3737.

If a send was accepted and you left Chat before it finished (for example by going to Datasets), the composer came back on return with the same prompt and Send enabled, even though the prompt was already in saved history.

Now, when Chat unmounts during an accepted send, the draft handoff snapshot also stores that send's submission ID, as long as the composer hasn't changed since the send. The ID is carried across later visits until the prompt shows up in history or the draft is edited. On return, if the snapshot has an accepted submission ID and saved history already has a user message with that prompt, the composer is cleared instead of restored. The system prompt, objective, temperature, scorer and converter pipelines are kept; text, attachments and converter working state are cleared, the same as after a normal completed send. Drafts without an accepted send, and drafts edited after the send (including added attachments or edited converter output), are restored as before. Nothing is resent automatically.

The match is on prompt text, so if the same text was sent earlier in the conversation, it also counts as saved.

This doesn't touch #3734 (carrying a draft across conversation switches).

Tests and Documentation

• New ChatWindow tests: (1) the issue's flow: unmount Chat during the send, remount after history has the prompt and reply; (2) an attachment added after a failed status read is kept; (3) the converter pipeline is kept; (4) leaving and returning twice while the send is in flight doesn't restore the prompt. Each fails without the fix and passes with it.
• New unit test for historyContainsAcceptedDraft in useChatDraftHandoff.test.tsx.
• npm run lint, npx tsc --noEmit and npm run build pass.
• Full npm run test:coverage: 4123 of 4145 passed. The 22 failures were timeouts in 12 suites while the machine was overloaded. Re-run on their own, those 12 suites passed (516/516).
• Playwright mock project, chat.spec.ts and routing.spec.ts: 33 passed. I didn't run the seeded or backend specs.

No docs changes needed.

[Copilot]

🟡 Changes recommended

Pending-send reconciliation and navigation can erase unsent draft edits, lose converter configuration, and restore an accepted prompt as resendable.

3 open issues

• Prevent stale status recovery from clearing newer composer edits · New
• Preserve converter configuration when clearing working state · New
• Retain accepted submission ID across composer handoffs · New

What changed in this PR

This PR addresses #3737 by reconciling preserved Chat drafts with saved history, preventing completed sends from reappearing as unsent prompts. Conversation-switch draft isolation (#3734) remains out of scope.

Changes:

• Records accepted submission IDs in draft handoff snapshots.
• Clears restored prompt content when its text matches saved user history.
• Adds utility and ChatWindow regression tests for navigation during a send.

File	Description
frontend/​src/​utils/​chatDraft.ts	Adds accepted-draft history matching.
frontend/​src/​types/​index.ts	Adds the optional accepted submission ID to drafts.
frontend/​src/​hooks/​useChatDraftHandoff.test.tsx	Tests accepted-draft matching conditions.
frontend/​src/​components/​Chat/​ChatWindow.tsx	Records accepted sends and reconciles restored drafts.
frontend/​src/​components/​Chat/​ChatWindow.test.tsx	Tests leaving Chat during a send and returning after completion.

_{Review effort: Balanced}

[Vishal Punjabi (vshalpnjabi)]

@microsoft-github-policy-service agree

[Vishal Punjabi (vshalpnjabi)]

Roman Lutz (@romanlutz) Conflicts with main are resolved and the branch is up to date. Copilot’s three notes were addressed in f8b7992 with replies on each thread. Ready for a look when you have a minute — thanks!