Previously test 4 used .take(N).toList() inside withTimeoutOrNull, so a
timeout discarded every received frame and the only failure signal was
"only got partial audio". When the production run flagged frame loss,
we couldn't tell whether the stream stalled mid-flight, never started
fanning out, or dropped scattered groups.
Drain into an external CopyOnWriteArrayList via .onEach { } so the
partial contents survive the timeout, then on failure surface:
- received N/100 with first/last arrival timestamps
- missingGroups summary as run-length ranges (e.g. [3-7,42,90-99])
- first/last 20 arrivals so the front and tail of the sequence are
visible without flooding stdout
The gap pattern alone narrows the diagnosis: front-loaded losses point
to subscribe-settle being too short, tail-loaded losses point to a
broadcaster shutdown race, scattered drops point to per-subscription
buffer overflow / datagram loss.
Claude
7e3d622399