chore: Flaky test fixed of ErrorsMonitor

tests/unit/test_errors_monitor.py

@@ -1,3 +1,5 @@
+from threading import Event
+from typing import Optional
 from unittest.mock import Mock
 
 from neptune_scale.core.components.errors_tracking import (
@@ -10,18 +12,28 @@ def test_errors_monitor():
     # given
     callback = Mock()
 
+    # Synchronization event
+    callback_called = Event()
+
+    # Modify the callback to set the event when called
+    def callback_with_event(exception: BaseException, last_called: Optional[float]) -> None:
+        callback(exception, last_called)
+        callback_called.set()
+
     # and
     errors_queue = ErrorsQueue()
-    errors_monitor = ErrorsMonitor(errors_queue=errors_queue, on_error_callback=callback)
+    errors_monitor = ErrorsMonitor(errors_queue=errors_queue, on_error_callback=callback_with_event)
+    errors_monitor.start()
 
     # when
     errors_queue.put(ValueError("error1"))
     errors_queue.flush()
-
-    # and
-    errors_monitor.start()
-    errors_monitor.work()
     errors_monitor.wake_up()
+
+    # then
+    assert callback_called.wait(timeout=5), "Callback was not called within the timeout"
+
+    # and - cleanup
     errors_monitor.interrupt()
     errors_monitor.join(timeout=5)