M8-R01: add configurable MQTT client identity

tests/test_mqtt_client.py

@@ -9,7 +9,7 @@ from unittest.mock import MagicMock, patch
 import pytest
 from fastapi.testclient import TestClient
 
-from app.integrations.mqtt import MqttManager
+from app.integrations.mqtt import MqttManager, mqtt_source_client_id, mqtt_test_client_id
 
 
 # ---------------------------------------------------------------------------
@@ -24,6 +24,7 @@ def _make_settings(
     mqtt_username: str = "",
     mqtt_password: str = "",
     mqtt_tls_enabled: bool = False,
+    mqtt_client_id: str = "home-automation",
     ha_discovery_prefix: str = "homeassistant",
 ):
     """Return a simple namespace that acts like a Settings object for MqttManager tests."""
@@ -34,6 +35,7 @@ def _make_settings(
     s.mqtt_username = mqtt_username
     s.mqtt_password = mqtt_password
     s.mqtt_tls_enabled = mqtt_tls_enabled
+    s.mqtt_client_id = mqtt_client_id
     s.ha_discovery_prefix = ha_discovery_prefix
     return s
 
@@ -120,6 +122,34 @@ def test_connect_creates_paho_client_with_version2() -> None:
     )
 
 
+def test_connect_uses_configured_client_id() -> None:
+    manager = MqttManager()
+    settings = _make_settings(mqtt_client_id="home-automation-dev")
+    mock_client = MagicMock()
+
+    with patch("app.integrations.mqtt.mqtt.Client", return_value=mock_client) as mock_cls:
+        manager.connect(settings)
+
+    assert mock_cls.call_args.kwargs["client_id"] == "home-automation-dev"
+
+
+def test_deployment_client_id_variants_are_distinct() -> None:
+    production_ids = {
+        "home-automation",
+        mqtt_source_client_id("home-automation", 7),
+        mqtt_test_client_id("home-automation"),
+    }
+    development_ids = {
+        "home-automation-dev",
+        mqtt_source_client_id("home-automation-dev", 7),
+        mqtt_test_client_id("home-automation-dev"),
+    }
+
+    assert len(production_ids) == 3
+    assert len(development_ids) == 3
+    assert production_ids.isdisjoint(development_ids)
+
+
 def test_connect_sets_credentials_when_username_provided() -> None:
     manager = MqttManager()
     settings = _make_settings(mqtt_username="user", mqtt_password="s3cr3t")
@@ -431,3 +461,17 @@ def test_run_mqtt_test_raises_connection_error_on_timeout() -> None:
         with patch("threading.Event", side_effect=_make_event):
             with pytest.raises(_MqttConnectionError, match="timed out"):
                 _run_mqtt_test(settings)
+
+
+def test_run_mqtt_test_uses_deployment_scoped_client_id() -> None:
+    from app.api.routes.api.config import _run_mqtt_test, _MqttConnectionError
+
+    settings = _make_settings(mqtt_client_id="home-automation-dev")
+    mock_client = MagicMock()
+    mock_client.connect.side_effect = OSError("Connection refused")
+
+    with patch("paho.mqtt.client.Client", return_value=mock_client) as mock_cls:
+        with pytest.raises(_MqttConnectionError):
+            _run_mqtt_test(settings)
+
+    assert mock_cls.call_args.kwargs["client_id"] == "home-automation-dev-test"