From 583aa66e64a7e4414980accbdb6578690074a933 Mon Sep 17 00:00:00 2001
From: petruki <31597636+petruki@users.noreply.github.com>
Date: Sun, 8 Feb 2026 11:07:36 -0800
Subject: [PATCH] feat: added Client.subscribe_notify_error() for error
 monitoring

---
 switcher_client/client.py                     |  8 ++++++++
 switcher_client/lib/utils/execution_logger.py |  5 +++++
 switcher_client/switcher.py                   |  7 +++++++
 tests/test_switcher_silent_mode.py            | 12 +++++++++++-
 4 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/switcher_client/client.py b/switcher_client/client.py
index 906fc14..b8ffe1e 100644
--- a/switcher_client/client.py
+++ b/switcher_client/client.py
@@ -178,6 +178,14 @@ def clear_resources() -> None:
         ExecutionLogger.clear_logger()
         GlobalSnapshot.clear()
         TimedMatch.terminate_worker()
+
+    @staticmethod
+    def subscribe_notify_error(callback: Callable[[Exception], None]) -> None:
+        """
+        Subscribe to notify when an asynchronous error is thrown.
+        It is usually used when throttle and silent mode are enabled.
+        """
+        ExecutionLogger.subscribe_notify_error(callback)
     
     @staticmethod
     def _is_check_snapshot_available(fetch_remote = False) -> bool:
diff --git a/switcher_client/lib/utils/execution_logger.py b/switcher_client/lib/utils/execution_logger.py
index da7ed43..86a6577 100644
--- a/switcher_client/lib/utils/execution_logger.py
+++ b/switcher_client/lib/utils/execution_logger.py
@@ -62,6 +62,11 @@ def clear_logger() -> None:
         """Clear all results"""
         global _logger
         _logger.clear()
+
+    @staticmethod
+    def subscribe_notify_error(callback: Callable[[Exception], None]) -> None:
+        """Subscribe to notify when an asynchronous error is thrown."""
+        ExecutionLogger._callback_error = callback
     
     @staticmethod
     def _has_execution(log: 'ExecutionLogger', key: str, input: Optional[List[List[str]]]) -> bool:
diff --git a/switcher_client/switcher.py b/switcher_client/switcher.py
index 112b94e..9e3da82 100644
--- a/switcher_client/switcher.py
+++ b/switcher_client/switcher.py
@@ -44,6 +44,8 @@ def _submit(self) -> ResultDetail:
 
             return self._execute_remote_criteria()
         except Exception as e:
+            self._notify_error(e)
+            
             if self._context.options.silent_mode:
                 RemoteAuth.update_silent_token()
                 return self._execute_local_criteria()
@@ -81,6 +83,11 @@ def _execute_api_checks(self):
         if RemoteAuth.is_token_expired():
             self.prepare(self._key)
 
+    def _notify_error(self, error: Exception):
+        """ Notify asynchronous error to the subscribed callback """
+        if ExecutionLogger._callback_error:
+            ExecutionLogger._callback_error(error)
+
     def _execute_remote_criteria(self):
         """ Execute remote criteria """
         token = GlobalAuth.get_token()
diff --git a/tests/test_switcher_silent_mode.py b/tests/test_switcher_silent_mode.py
index 61051ae..84e0849 100644
--- a/tests/test_switcher_silent_mode.py
+++ b/tests/test_switcher_silent_mode.py
@@ -6,6 +6,8 @@
 from switcher_client import Client
 from switcher_client.lib.globals.global_context import ContextOptions
 
+async_error = None
+
 def test_silent_mode_for_check_criteria(httpx_mock):
     """ Should use the silent mode when the remote API is not available for check criteria """
 
@@ -15,15 +17,19 @@ def test_silent_mode_for_check_criteria(httpx_mock):
     given_check_health(httpx_mock, status=500)
     given_context(silent_mode='1s')
 
+    Client.subscribe_notify_error(lambda error: globals().update(async_error=str(error)))
     switcher = Client.get_switcher('FF2FOR2022')
 
     # test
     # assert silent mode being used while registering the error
     assert switcher.is_on('FF2FOR2022')
+    assert async_error == '[check_criteria] failed with status: 429'
 
     # assert silent mode being used in the next call
     time.sleep(1.5)
+    globals().update(async_error=None)
     assert switcher.is_on('FF2FOR2022')
+    assert async_error is None
 
 def test_silent_mode_for_check_criteria_restabilished(httpx_mock):
     """ Should retry check criteria once the remote API is restabilished and the token is renewed """
@@ -33,17 +39,22 @@ def test_silent_mode_for_check_criteria_restabilished(httpx_mock):
     given_check_criteria(httpx_mock, key='FF2FOR2022', response={'error': 'Too many requests'}, status=429)
     given_context(silent_mode='1s')
 
+    Client.subscribe_notify_error(lambda error: globals().update(async_error=str(error)))
     switcher = Client.get_switcher('FF2FOR2022')
 
     # test
     # assert silent mode being used while registering the error
     assert switcher.is_on('FF2FOR2022')
+    assert async_error == '[check_criteria] failed with status: 429'
 
     # assert from remote API once the API is restabilished and the token is renewed
     given_check_criteria(httpx_mock, key='FF2FOR2022', response={'result': True}, status=200)
     given_check_health(httpx_mock, status=200)
+
     time.sleep(1.5)
+    globals().update(async_error=None)
     assert switcher.is_on('FF2FOR2022')
+    assert async_error is None
 
 # Helpers
 
@@ -85,4 +96,3 @@ def given_check_health(httpx_mock: HTTPXMock, status=200):
         method='GET',
         status_code=status,
     )
-