fix: don't reconnect on no active subscribers

roborock/mqtt/roborock_session.py

@@ -27,7 +27,7 @@
 _LOGGER = logging.getLogger(__name__)
 _MQTT_LOGGER = logging.getLogger(f"{__name__}.aiomqtt")
 
-CLIENT_KEEPALIVE = datetime.timedelta(seconds=60)
+CLIENT_KEEPALIVE = datetime.timedelta(seconds=45)
 TOPIC_KEEPALIVE = datetime.timedelta(seconds=60)
 
 # Exponential backoff parameters
@@ -175,6 +175,16 @@ async def _run_reconnect_loop(self, start_future: asyncio.Future[None] | None) -
             if self._stop:
                 _LOGGER.debug("MQTT session closed, stopping retry loop")
                 return
+            if not self._client_subscribed_topics and not self._listeners.keys():
+                _LOGGER.debug("MQTT session disconnected with no active subscriptions, deferring reconnect")
+                self._diagnostics.increment("reconnect_deferred")
+                while not self._stop and not self._client_subscribed_topics and not self._listeners.keys():
+                    await asyncio.sleep(0.1)
+                if self._stop:
+                    _LOGGER.debug("MQTT session closed while waiting for active subscriptions")
+                    return
+                self._backoff = MIN_BACKOFF_INTERVAL
+                continue
             _LOGGER.info("MQTT session disconnected, retrying in %s seconds", self._backoff.total_seconds())
             self._diagnostics.increment("reconnect_wait")
             await asyncio.sleep(self._backoff.total_seconds())

tests/e2e/__snapshots__/test_mqtt_session.ambr

@@ -1,7 +1,7 @@
 # serializer version: 1
 # name: test_session_e2e_publish_message
   [mqtt >]
-  00000000  10 21 00 04 4d 51 54 54 05 c2 00 3c 00 00 00 00  |.!..MQTT...<....|
+  00000000  10 21 00 04 4d 51 54 54 05 c2 00 2d 00 00 00 00  |.!..MQTT...-....|
   00000010  08 75 73 65 72 6e 61 6d 65 00 08 70 61 73 73 77  |.username..passw|
   00000020  6f 72 64                                         |ord|
   [mqtt <]
@@ -15,7 +15,7 @@
 # ---
 # name: test_session_e2e_receive_message
   [mqtt >]
-  00000000  10 21 00 04 4d 51 54 54 05 c2 00 3c 00 00 00 00  |.!..MQTT...<....|
+  00000000  10 21 00 04 4d 51 54 54 05 c2 00 2d 00 00 00 00  |.!..MQTT...-....|
   00000010  08 75 73 65 72 6e 61 6d 65 00 08 70 61 73 73 77  |.username..passw|
   00000020  6f 72 64                                         |ord|
   [mqtt <]

tests/mqtt/test_roborock_session.py

@@ -529,8 +529,37 @@ def succeed_then_fail_unauthorized() -> Any:
     session = await create_mqtt_session(params)
     assert session.connected
 
+    # Keep an active subscription so reconnect attempts are not deferred.
+    await session.subscribe("topic-1", Subscriber().append)
+
     try:
         async with asyncio.timeout(10):
             assert await unauthorized.wait()
     finally:
         await session.close()
+
+
+async def test_session_defers_reconnect_when_idle() -> None:
+    """Test that reconnects are deferred when there are no active subscriptions."""
+
+    session = RoborockMqttSession(FAKE_PARAMS)
+    start_future: asyncio.Future[None] = asyncio.Future()
+    connect_attempts = 0
+
+    async def fake_run_connection(start: asyncio.Future[None] | None) -> None:
+        nonlocal connect_attempts
+        connect_attempts += 1
+        if start and not start.done():
+            start.set_result(None)
+
+    with patch.object(session, "_run_connection", side_effect=fake_run_connection):
+        reconnect_task = asyncio.create_task(session._run_reconnect_loop(start_future))
+        try:
+            await start_future
+            await asyncio.sleep(0.1)
+            assert connect_attempts == 1
+            assert session._diagnostics.as_dict().get("reconnect_deferred", 0) >= 1
+        finally:
+            session._stop = True
+            reconnect_task.cancel()
+            await asyncio.gather(reconnect_task, return_exceptions=True)