M8-R02: report DSMR MQTT source health

tests/test_mqtt_subscribe.py

@@ -437,6 +437,88 @@ def test_source_sync_connack_before_connect_returns_subscribes_all_topics() -> N
     assert client.subscribed == ["telegram/topic", "tariff/topic"]
 
 
+def test_source_health_tracks_connack_disconnect_and_ignores_stale_callbacks() -> None:
+    """A source is connecting until CONNACK, and old generations cannot rewrite health."""
+    manager = MqttManager()
+    old_client = MagicMock()
+    new_client = MagicMock()
+    old_states: list[str] = []
+    new_states: list[str] = []
+    kwargs = {
+        "host": "broker.test",
+        "port": 1883,
+        "username": "",
+        "password": "",
+        "tls_enabled": False,
+        "subscriptions": {"topic": lambda _payload: None},
+    }
+    with patch("app.integrations.mqtt.mqtt.Client", side_effect=[old_client, new_client]):
+        assert manager.replace_source(1, **kwargs, state_handler=old_states.append)
+        assert old_states == ["connecting"]
+        assert manager.replace_source(1, **kwargs, state_handler=new_states.append)
+
+    accepted = MagicMock()
+    accepted.is_failure = False
+    old_client.on_connect(old_client, None, MagicMock(), accepted, None)
+    old_client.on_disconnect(old_client, None, MagicMock(), MagicMock(), None)
+    assert old_states == ["connecting"]
+
+    new_client.on_connect(new_client, None, MagicMock(), accepted, None)
+    new_client.on_disconnect(new_client, None, MagicMock(), MagicMock(), None)
+    assert new_states == ["connecting", "online", "error"]
+
+
+def test_source_health_rejected_connack_reports_error_without_disconnect() -> None:
+    """A failed CONNACK is distinct from a later disconnect callback."""
+    manager = MqttManager()
+    client = MagicMock()
+    states: list[str] = []
+    with patch("app.integrations.mqtt.mqtt.Client", return_value=client):
+        assert manager.replace_source(
+            1, host="broker.test", port=1883, username="", password="", tls_enabled=False,
+            subscriptions={"topic": lambda _payload: None}, state_handler=states.append,
+        )
+
+    accepted = MagicMock()
+    accepted.is_failure = False
+    refused = MagicMock()
+    refused.is_failure = True
+    client.on_connect(client, None, MagicMock(), accepted, None)
+    client.on_connect(client, None, MagicMock(), refused, None)
+
+    assert states == ["connecting", "online", "error"]
+    assert 1 not in manager._source_connected
+
+
+def test_source_health_disconnect_then_reconnect_connack_is_ordered_and_isolated() -> None:
+    """One source's reconnect sequence cannot change another source's health."""
+    manager = MqttManager()
+    first_client = MagicMock()
+    second_client = MagicMock()
+    first_states: list[str] = []
+    second_states: list[str] = []
+    kwargs = {
+        "host": "broker.test",
+        "port": 1883,
+        "username": "",
+        "password": "",
+        "tls_enabled": False,
+        "subscriptions": {"topic": lambda _payload: None},
+    }
+    with patch("app.integrations.mqtt.mqtt.Client", side_effect=[first_client, second_client]):
+        assert manager.replace_source(1, **kwargs, state_handler=first_states.append)
+        assert manager.replace_source(2, **kwargs, state_handler=second_states.append)
+
+    accepted = MagicMock()
+    accepted.is_failure = False
+    first_client.on_connect(first_client, None, MagicMock(), accepted, None)
+    first_client.on_disconnect(first_client, None, MagicMock(), MagicMock(), None)
+    first_client.on_connect(first_client, None, MagicMock(), accepted, None)
+
+    assert first_states == ["connecting", "online", "error", "online"]
+    assert second_states == ["connecting"]
+
+
 def test_source_teardown_with_joining_loop_stop_waits_for_callback_before_aba() -> None:
     """loop_stop may join a callback that needs the manager lock to finish."""
     manager = MqttManager()