adds test for starting and stopping tasks

tests/data_service/test_task_manager.py

@@ -1,3 +1,4 @@
+import asyncio
 import logging
 
 import pydase
@@ -95,3 +96,30 @@ async def test_DataService_subclass_list_autostart_task_callback(
     assert "'sub_services_list[0].my_other_task' changed to '{}'" in caplog.text
     assert "'sub_services_list[1].my_task' changed to '{}'" in caplog.text
     assert "'sub_services_list[1].my_other_task' changed to '{}'" in caplog.text
+
+
+@pytest.mark.asyncio
+async def test_start_and_stop_task_methods(caplog: LogCaptureFixture) -> None:
+    class MyService(pydase.DataService):
+        def __init__(self) -> None:
+            super().__init__()
+
+        async def my_task(self, param: str) -> None:
+            while True:
+                logger.debug("Logging param: %s", param)
+                await asyncio.sleep(0.1)
+
+    # Your test code here
+    service_instance = MyService()
+    state_manager = StateManager(service_instance)
+    DataServiceObserver(state_manager)
+    service_instance.start_my_task("Hello")
+    await asyncio.sleep(0.01)
+
+    assert "'my_task' changed to '{'param': 'Hello'}'" in caplog.text
+    assert "Logging param: Hello" in caplog.text
+    caplog.clear()
+
+    service_instance.stop_my_task()
+    await asyncio.sleep(0.01)
+    assert "Task 'my_task' was cancelled" in caplog.text