The channelFlow conversion in f17e7ad fixed `MoqLiteNestsListener.announces`
but the SAME `IllegalStateException: Flow invariant is violated` kept
firing in the next two-phone repro (commit f17e7ad, run 15:46:51) — this
time the offending `flow{}` was one layer up, in
`ReconnectingNestsListener.announces`:
override fun announces(): Flow<RoomAnnouncement> =
flow {
activeListener.collectLatest { listener ->
...
runCatching {
listener.announces().collect { emit(it) } // <-- HERE
}
}
}
`Flow.collectLatest { lambda }` cancels and restarts a CHILD coroutine
for each upstream emission. The lambda body runs in that child, NOT in
the surrounding flow{} body's coroutine. So when the lambda invokes
`emit(it)`, it's emitting from a child coroutine. `flow{}`'s
SafeFlow guard rejects this with the same "Emission from another
coroutine is detected" error the inner listener was throwing before
my last fix.
Net effect on the user's repro: the inner channelFlow now correctly
sends RoomAnnouncement to the wrapper's `listener.announces().collect`
lambda, but that lambda's `emit(it)` to the wrapper's flow{} body
fails the same SafeFlow check, the wrapper's runCatching swallows the
exception (as `iter=2 inner collect ended IllegalStateException ...
fwd=1`), `_announcedSpeakers` stays empty, cliff detector never fires.
Fix: convert `ReconnectingNestsListener.announces` from `flow{} + emit`
to `channelFlow{} + send`, matching the inner listener's shape. The
combination of `channelFlow + collectLatest + send` is the canonical
pattern in kotlinx-coroutines for "switch-map" semantics with cross-
coroutine production. `awaitClose { }` is empty because `collectLatest`
on an infinite-StateFlow never completes naturally — cancellation
propagates through structured concurrency when the consumer cancels
the channelFlow.
Tests: every nestsClient + commons unit test still passes, including
the 12 CliffDetectorTest cases pinning the predicate's behaviour.
Together with f17e7ad (inner channelFlow), this should finally close
the chain: inner emits RoomAnnouncement on its channelFlow → wrapper's
collectLatest receives it inside its child coroutine → wrapper's
channelFlow.send forwards across the channel → consumer's
observeAnnounces collect receives → `_announcedSpeakers` populates →
cliff detector tick reports `announced=1` → on a real cliff event the
recycle fires.
Claude
457e0f5997