Mpirnovar update error (#433)

* updare error log message

* test for the log message

* upate to generic exception

Author: Mat001

optimizely/config_manager.py

@@ -420,9 +420,9 @@ def _run(self) -> None:
                 if self.stopped.wait(self.update_interval):
                     self.stopped.clear()
                     break
-        except (OSError, OverflowError) as err:
+        except Exception as err:
             self.logger.error(
-                f'Provided update_interval value may be too big. Error: {err}'
+                f'Thread for background datafile polling failed. Error: {err}'
             )
             raise
 

tests/test_config_manager.py

@@ -494,6 +494,32 @@ def test_fetch_datafile__request_exception_raised(self, _):
         self.assertEqual(test_headers['Last-Modified'], project_config_manager.last_modified)
         self.assertIsInstance(project_config_manager.get_config(), project_config.ProjectConfig)
 
+    def test_fetch_datafile__exception_polling_thread_failed(self, _):
+        """ Test that exception is raised when polling thread stops. """
+        sdk_key = 'some_key'
+        mock_logger = mock.Mock()
+
+        test_headers = {'Last-Modified': 'New Time'}
+        test_datafile = json.dumps(self.config_dict_with_features)
+        test_response = requests.Response()
+        test_response.status_code = 200
+        test_response.headers = test_headers
+        test_response._content = test_datafile
+
+        with mock.patch('requests.get', return_value=test_response):
+            project_config_manager = config_manager.PollingConfigManager(sdk_key=sdk_key,
+                                                                         logger=mock_logger,
+                                                                         update_interval=12345678912345)
+
+            project_config_manager.stop()
+
+            # verify the error log message
+            log_messages = [args[0] for args, _ in mock_logger.error.call_args_list]
+            for message in log_messages:
+                if "Thread for background datafile polling failed. " \
+                   "Error: timestamp too large to convert to C _PyTime_t" not in message:
+                    assert False
+
     def test_is_running(self, _):
         """ Test that polling thread is running after instance of PollingConfigManager is created. """
         with mock.patch('optimizely.config_manager.PollingConfigManager.fetch_datafile'):