adds tests for data service type change warnings

tests/data_service/test_data_service.py

@@ -0,0 +1,29 @@
+import pydase.units as u
+from pydase import DataService
+from pydase.data_service.data_service_observer import DataServiceObserver
+from pydase.data_service.state_manager import StateManager
+from pytest import LogCaptureFixture
+
+
+def test_unexpected_type_change_warning(caplog: LogCaptureFixture) -> None:
+    class ServiceClass(DataService):
+        attr_1 = 1.0
+        current = 1.0 * u.units.A
+
+    service_instance = ServiceClass()
+    state_manager = StateManager(service_instance)
+    DataServiceObserver(state_manager)
+    service_instance.attr_1 = 2
+
+    assert "'attr_1' changed to '2'" in caplog.text
+    assert (
+        "Type of 'attr_1' changed from 'float' to 'int'. This may have unwanted "
+        "side effects! Consider setting it to 'float' directly." in caplog.text
+    )
+
+    service_instance.current = 2
+    assert "'current' changed to '2'" in caplog.text
+    assert (
+        "Type of 'current' changed from 'Quantity' to 'int'. This may have unwanted "
+        "side effects! Consider setting it to 'Quantity' directly." in caplog.text
+    )