M5: use DB-merged runtime settings for MQTT/discovery; add MQTT test button; move Expose panel into config accordion

tests/test_api_config.py

@@ -3,7 +3,7 @@
 from __future__ import annotations
 
 import sqlite3
-from unittest.mock import patch
+from unittest.mock import MagicMock, patch
 
 from fastapi.testclient import TestClient
 
@@ -656,3 +656,90 @@ def test_put_config_bool_field_roundtrip_true_false(
     finally:
         conn.close()
     assert rows.get("MQTT_ENABLED") == "false"
+
+
+# ---------------------------------------------------------------------------
+# M5-fix2: DB-config → runtime settings (Issue 2 regression assertions)
+# ---------------------------------------------------------------------------
+
+def test_put_config_mqtt_reconnect_uses_db_merged_settings(
+    client: TestClient, test_database_urls
+) -> None:
+    """PUT /api/config with MQTT keys must reconnect with DB-merged settings,
+    not bootstrap-only settings.  Asserts that mqtt_manager.reconnect receives
+    settings where mqtt_enabled=True and mqtt_broker_host matches the submitted value.
+    """
+    _login(client)
+
+    target_host = "mqtt.example.com"
+    payload = _full_config_payload({
+        "MQTT_ENABLED": "true",
+        "MQTT_BROKER_HOST": target_host,
+    })
+
+    mock_mgr = MagicMock()
+    mock_mgr.is_configured.return_value = True
+
+    with patch("app.api.routes.api.config.mqtt_manager", mock_mgr):
+        resp = client.put(
+            "/api/config",
+            json={"updates": payload},
+            headers={"X-CSRF-Token": "token"},
+        )
+
+    assert resp.status_code == 200
+
+    # reconnect must have been called once
+    assert mock_mgr.reconnect.call_count == 1, (
+        f"Expected mqtt_manager.reconnect called once, got {mock_mgr.reconnect.call_count}"
+    )
+    reconnect_settings = mock_mgr.reconnect.call_args[0][0]
+    assert reconnect_settings.mqtt_enabled is True, (
+        f"reconnect settings.mqtt_enabled must be True, got {reconnect_settings.mqtt_enabled!r}"
+    )
+    assert reconnect_settings.mqtt_broker_host == target_host, (
+        f"reconnect settings.mqtt_broker_host must be {target_host!r}, "
+        f"got {reconnect_settings.mqtt_broker_host!r}"
+    )
+
+
+def test_post_mqtt_test_uses_db_broker_host(
+    client: TestClient, test_database_urls
+) -> None:
+    """POST /api/config/mqtt/test must use the DB-stored broker host, not env/bootstrap."""
+    _login(client)
+
+    db_host = "broker.db-configured.local"
+
+    # First write the MQTT config to DB via PUT /api/config
+    payload_save = _full_config_payload({
+        "MQTT_ENABLED": "true",
+        "MQTT_BROKER_HOST": db_host,
+    })
+    with patch("app.api.routes.api.config.mqtt_manager"):
+        save_resp = client.put(
+            "/api/config",
+            json={"updates": payload_save},
+            headers={"X-CSRF-Token": "token"},
+        )
+    assert save_resp.status_code == 200
+
+    # Now POST /api/config/mqtt/test — capture the host that _run_mqtt_test uses.
+    captured_host: list[str] = []
+
+    def _fake_run_mqtt_test(settings):
+        captured_host.append(settings.mqtt_broker_host)
+        # simulate success by just returning
+        return
+
+    with patch("app.api.routes.api.config._run_mqtt_test", side_effect=_fake_run_mqtt_test):
+        resp = client.post(
+            "/api/config/mqtt/test",
+            headers={"X-CSRF-Token": "token"},
+        )
+
+    assert resp.status_code == 200
+    assert len(captured_host) == 1, "Expected _run_mqtt_test to be called once"
+    assert captured_host[0] == db_host, (
+        f"Expected mqtt test to use DB host {db_host!r}, got {captured_host[0]!r}"
+    )