MQTT-FIX-T01: make main MQTT client lifecycle idempotent

tests/test_mqtt_scheduler.py

@@ -0,0 +1,68 @@
+"""Offline regression coverage for scheduler-driven MQTT recovery."""
+from __future__ import annotations
+
+from unittest.mock import MagicMock, patch
+
+from app.integrations.mqtt import MqttManager
+from app.main import _run_scheduled_ha_state_publish
+
+
+def test_scheduler_reuses_manager_across_disconnects_then_subscribes_and_publishes() -> None:
+    session = MagicMock()
+    session_local = MagicMock(return_value=session)
+    settings = MagicMock(
+        mqtt_enabled=True,
+        mqtt_broker_host="synthetic-broker",
+        mqtt_broker_port=1883,
+        mqtt_username="",
+        mqtt_password="",
+        mqtt_tls_enabled=False,
+        mqtt_client_id="offline-test",
+    )
+    manager = MqttManager()
+    clients: list[MagicMock] = []
+
+    def make_client(*_args: object, **_kwargs: object) -> MagicMock:
+        client = MagicMock()
+        clients.append(client)
+        return client
+
+    manager.subscribe("homeassistant/status", lambda _payload: None)
+
+    def publish_states(_session: object) -> None:
+        manager.publish("homeassistant/state", b"state", retain=True)
+
+    with (
+        patch("app.main.get_session_local", return_value=session_local),
+        patch("app.main.build_runtime_settings", return_value=settings),
+        patch("app.main.get_settings", return_value=MagicMock()),
+        patch("app.main.mqtt_manager", manager),
+        patch("app.main.publish_discovery") as publish_discovery,
+        patch("app.main.publish_states", side_effect=publish_states),
+        patch("app.integrations.mqtt.mqtt.Client", side_effect=make_client),
+    ):
+        for _ in range(3):
+            _run_scheduled_ha_state_publish()
+            assert len(clients) == 1
+            assert clients[0].loop_start.call_count == 1
+            clients[0].on_disconnect(
+                clients[0], None, None, MagicMock(is_failure=True), None
+            )
+            assert not manager.is_connected
+
+        # A subsequent scheduler turn sees Paho's existing loop retrying; it
+        # must not replace that client. Simulate the successful CONNACK.
+        _run_scheduled_ha_state_publish()
+        assert len(clients) == 1
+        clients[0].on_connect(clients[0], None, None, MagicMock(is_failure=False), None)
+
+        assert manager.is_connected
+        clients[0].subscribe.assert_called_with("homeassistant/status")
+        _run_scheduled_ha_state_publish()
+        assert len(clients) == 1
+        clients[0].publish.assert_called_once_with(
+            "homeassistant/state", payload=b"state", qos=0, retain=True
+        )
+        assert publish_discovery.call_count == 5
+        assert session.close.call_count == 5
+        manager.disconnect()