ensure the UI operation finished

Author: ReimarBauer

tests/_test_msui/test_msui.py

@@ -75,9 +75,15 @@ def test_multiple_times_save_filename(qtbot, tmp_path):
     assert os.path.exists(filename) is False
     # verify that we can save the file multiple times
     msui.save_flight_track(filename)
-    assert os.path.exists(filename)
+    def assert_wait_until_saved():
+        assert os.path.exists(filename)
+    qtbot.wait_until(assert_wait_until_saved)
     first_timestamp = os.path.getmtime(filename)
+    # file update
     msui.save_handler()
+    def assert_wait_until_updated():
+        assert os.path.exists(filename) and os.path.getmtime(filename) > first_timestamp
+    qtbot.wait_until(assert_wait_until_updated)
     second_timestamp = os.path.getmtime(filename)
     with mock.patch("PyQt5.QtWidgets.QMessageBox.warning", return_value=QtWidgets.QMessageBox.Yes):
         msui.close()