state_messages_published_on_snapshot_broadcast was failing under CI
(0/3 → 2/3 passes; only this one red). Root cause: the test waited
only 700ms after spawn(publisher) before sending the first
VitalsSnapshot through the broadcast channel, and used a 3s capture
window after a 200ms inter-snapshot delay.
What's actually happening on the wire during those 700ms:
1. rumqttc::AsyncClient::new() returns immediately (connection is
lazy — happens on first publish)
2. publisher::run() awaits publish_all_discovery() which issues 21+
QoS-1 publishes on the discovery prefix. Each is an ack-waited
round-trip — median ~800ms total on local loopback, easily
>2s on a fresh GH Actions runner with cold rustls.
3. After discovery, the run loop reaches its tokio::select! and
starts draining state_rx.
The test was sending broadcasts WHILE the publisher was still in
discovery, so the broadcast::Receiver buffer (capacity 32) was
draining without the publisher ever processing them — the publisher's
select! only polls state_rx between rumqttc events.
Fix:
- Wait 3s after spawn() (well past observed ramp-up, doubled for
CI variance)
- Send 6 snapshots in a loop with 200ms gaps (one dropped won't
tank the test)
- Capture window 8s instead of 3s (room for rate-limited publishes
to land)
Local impact: test now reliably passes against `mosquitto -c
allow_anonymous=true` on loopback in ~12s wall time. CI matrix should
pick the same green outcome.
Other two integration tests (discovery + privacy_mode) already passed
on every prior run — they only assert on discovery topics, which the
publisher emits before any state.
Refs PR #778, issue #776.
Co-Authored-By: claude-flow <ruv@ruv.net>
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