Added test and small date fix.

tests/test_mqtt.py

@@ -0,0 +1,37 @@
+# tests/test_mqtt.py
+
+import pytest
+import socket
+from tools.mqtt import MQTT
+
+
+def test_mqtt_ip_resolution_success(mocker):
+    # Force socket.gethostbyname to simulate a working DNS
+    mocker.patch("socket.gethostbyname", return_value="10.11.0.33")
+
+    mqtt_client = MQTT()
+    assert mqtt_client.IP == "10.11.0.33"
+
+
+def test_mqtt_ip_resolution_fallback(mocker, caplog):
+    # Simulate a DNS timeout (like what happened to you earlier!)
+    mocker.patch("socket.gethostbyname", side_effect=socket.timeout("DNS down"))
+
+    mqtt_client = MQTT()
+
+    # Assert it fell back to the static IP from your .env / constants
+    assert mqtt_client.IP == "10.11.0.33"
+    assert "Falling back to static IP" in caplog.text
+
+
+def test_mqtt_send_error_handling(mocker, caplog):
+    # Mock the actual publish function to throw a connection error
+    mocker.patch(
+        "tools.mqtt.mqtt_publish", side_effect=ConnectionRefusedError("Broker offline")
+    )
+
+    mqtt_client = MQTT()
+    mqtt_client.send({"temp": 20})
+
+    # Assert it didn't crash, and logged the error
+    assert "MQTT data couldn't be sent" in caplog.text