This PR establishes the intended behavior as an executable contract
before a refactor of the cell runtime begins. It also fixes cases where
a second observer or termination request could replace an existing
response channel and leave the original caller unresolved.
### Behavior codified
- A cell can yield output and subsequently resume to completion.
- A caller can run a cell until it has no immediately runnable work,
receive its accumulated output and outstanding tool-call IDs, and then
resume the same cell when the awaited work is available.
- Each cell admits one active observer:
- a second observer receives an explicit busy error
- the existing observer remains registered and is not displaced
- A natural result (conclusion of the js module) that has already
reached the cell controller wins over a later termination request.
- Otherwise, termination preempts execution and resolves both:
- the active observer, if present
- the caller requesting termination
- Repeated termination requests are rejected while termination is
already in progress.
- Terminal responses are sent only after outstanding callback work has
been handled:
- natural completion drains notifications and cancels outstanding tool
calls
- termination cancels and drains both notification and tool callbacks.
- Cell removal and cell_closed notification happen after callback
cleanup
Channing CongerandGitHub
e93516e259