fix: verify MQTT connection requires successful subscription

roborock/devices/rpc/v1_channel.py

@@ -204,8 +204,14 @@ def is_local_connected(self) -> bool:
 
     @property
     def is_mqtt_connected(self) -> bool:
-        """Return whether MQTT connection is available."""
-        return self._mqtt_channel.is_connected
+        """Return whether MQTT connection is available for the device.
+
+        This requires the MQTT session to be connected to the broker and
+        the subscription to the device's topic to have successfully
+        been established (to handle cases where the device is offline
+        or deleted).
+        """
+        return self._mqtt_channel.is_connected and self._mqtt_unsub is not None
 
     @property
     def rpc_channel(self) -> V1RpcChannel:

tests/devices/rpc/test_v1_channel.py

@@ -233,6 +233,56 @@ async def test_v1_channel_mqtt_disconnected(
     assert not mock_mqtt_channel.subscribers
 
 
+async def test_v1_channel_mqtt_subscription_fails_local_succeeds(
+    v1_channel: V1Channel,
+    mock_mqtt_channel: FakeChannel,
+    device_cache: DeviceCache,
+) -> None:
+    """Test MQTT subscription failure while local connection succeeds."""
+    # Pre-populate cache so we don't query network info via MQTT
+    device_cache_data = await device_cache.get()
+    device_cache_data.network_info = TEST_NETWORKING_INFO
+    await device_cache.set(device_cache_data)
+
+    # Simulate MQTT subscription failing
+    mock_mqtt_channel.subscribe.side_effect = RoborockException("MQTT subscription failed")
+
+    # Subscribe should succeed via local fallback
+    callback = Mock()
+    unsub = await v1_channel.subscribe(callback)
+
+    # Verify MQTT is not reported as connected, but local is
+    assert not v1_channel.is_mqtt_connected
+    assert v1_channel.is_local_connected
+    assert v1_channel.is_connected
+
+    unsub()
+
+
+async def test_v1_channel_all_connection_attempts_fail(
+    v1_channel: V1Channel,
+    mock_mqtt_channel: FakeChannel,
+    mock_local_channel: FakeChannel,
+    device_cache: DeviceCache,
+) -> None:
+    """Test when both local connect and MQTT subscribe fail."""
+    # Pre-populate cache so we don't query network info via MQTT
+    device_cache_data = await device_cache.get()
+    device_cache_data.network_info = TEST_NETWORKING_INFO
+    await device_cache.set(device_cache_data)
+
+    mock_local_channel.connect.side_effect = RoborockException("local down")
+    mock_mqtt_channel.subscribe.side_effect = RoborockException("MQTT subscription failed")
+
+    with pytest.raises(RoborockException):
+        await v1_channel.subscribe(Mock())
+
+    # After a failed subscription, properties should reflect no active connection
+    assert not v1_channel.is_mqtt_connected
+    assert not v1_channel.is_local_connected
+    assert not v1_channel.is_connected
+
+
 async def test_v1_channel_subscribe_local_success(
     v1_channel: V1Channel,
     mock_mqtt_channel: Mock,