A customer's question is drawn once, however long the answer takes

[thankywal]

What a visitor saw

On the demo shop's widget, one question typed → two identical bubbles → one answer.

The mechanism

The widget draws the question straight away and calls /send. While the model thinks (seconds), the six-second poll — there to collect what a person on the shop's side may type — asked for every row after the last it knew. The Worker had already stored the question, handed it back, and the widget drew it again. Two writers to one transcript.

It cannot happen on the very first message (no session to poll for until the Worker has answered once); from the second message on it happens whenever the reply outlasts the time to the next tick — which is most replies.

The rule now (widget.ts, 24 lines)

• A turn that is out is drawn by its own answer. While a send is in flight the poll does not go out, and one already out that returns mid-send is discarded — the send's answer carries the reply and the seq covering both rows.
• Every row is drawn once, by seq. A late poll brings nothing new.

Tests — 960 passing (+4)

a-question-is-drawn-once.test.ts runs the real widget script against a stub of the DOM it touches, with fetch under the test's control so the poll lands mid-send:

• drawn once when the tick fires during the send;
• drawn once when a poll asked before the send is answered during it;
• a person's handover reply from the shop is drawn once and not again on the next poll;
• after a send, the next poll asks from the reply's seq.

With the bug put back (git stash the widget), 3 of 4 fail. The existing new Function(script) syntax check still passes.

After merge

bash scripts/first-sync.sh thankywal/muxel-demo → Cloudflare rebuilds the demo Worker (~3 min) → the widget at /w/… serves the new script.

🤖 Generated with Claude Code

https://claude.ai/code/session_01NDkiHs276KQhSWxQnHQdLg