fix(client-reports): Emit callback_error when a processor raises (#8005)

We're not recording the correct reason if a event/error processor raises
(should be `callback_error`).

Closes
https://linear.app/getsentry/issue/PY-2888/drop-events-if-a-processor-raises

Author: sentrivana

sentry_sdk/client.py

@@ -464,13 +464,9 @@ def _prepare_event(
         if scope is not None:
             event_ = scope.apply_to_event(event, hint, self.options)
 
-            # one of the event/error processors returned None
+            # one of the event/error processors returned None or raised;
+            # the client report is recorded in Scope._drop
             if event_ is None:
-                if self.transport:
-                    self.transport.record_lost_event(
-                        "event_processor",
-                        data_category="error",
-                    )
                 return None
 
             event = event_

sentry_sdk/scope.py

@@ -1458,10 +1458,6 @@ def _apply_user_attributes_to_telemetry(
             ):
                 attributes[attribute_name] = self._user[user_attribute]
 
-    def _drop(self, cause: "Any", ty: str) -> "Optional[Any]":
-        logger.info("%s (%s) dropped event", ty, cause)
-        return None
-
     def run_error_processors(self, event: "Event", hint: "Hint") -> "Optional[Event]":
         """
         Runs the error processors on the event and returns the modified event.
@@ -1476,10 +1472,22 @@ def run_error_processors(self, event: "Event", hint: "Hint") -> "Optional[Event]
 
             for error_processor in error_processors:
                 new_event = None
+                exception_raised = False
                 with capture_internal_exceptions():
-                    new_event = error_processor(event, exc_info)
+                    try:
+                        new_event = error_processor(event, exc_info)
+                    except Exception:
+                        exception_raised = True
+                        raise
                 if new_event is None:
-                    return self._drop(error_processor, "error processor")
+                    logger.info("%s (error processor) dropped event", error_processor)
+                    transport = sentry_sdk.get_client().transport
+                    if transport:
+                        transport.record_lost_event(
+                            "callback_error" if exception_raised else "event_processor",
+                            data_category="error",
+                        )
+                    return None
 
                 event = new_event
 
@@ -1506,10 +1514,23 @@ def run_event_processors(self, event: "Event", hint: "Hint") -> "Optional[Event]
 
             for event_processor in event_processors:
                 new_event = None
+                exception_raised = False
                 with capture_internal_exceptions():
-                    new_event = event_processor(event, hint)
+                    try:
+                        new_event = event_processor(event, hint)
+                    except Exception:
+                        exception_raised = True
+                        raise
                 if new_event is None:
-                    return self._drop(event_processor, "event processor")
+                    logger.info("%s (event processor) dropped event", event_processor)
+                    transport = sentry_sdk.get_client().transport
+                    if transport:
+                        transport.record_lost_event(
+                            "callback_error" if exception_raised else "event_processor",
+                            data_category="error",
+                        )
+                    return None
+
                 event = new_event
 
         return event

tests/test_basics.py

@@ -734,7 +734,7 @@ def bad_processor(event, hint):
     capture_message("should be dropped")
 
     assert len(events) == 0
-    assert ("event_processor", "error", None, 1) in record_lost_event_calls
+    assert record_lost_event_calls == [("callback_error", "error", None, 1)]
 
 
 @pytest.mark.tests_internal_exceptions
@@ -757,7 +757,7 @@ def bad_error_processor(event, exc_info):
         capture_exception()
 
     assert len(events) == 0
-    assert ("event_processor", "error", None, 1) in record_lost_event_calls
+    assert record_lost_event_calls == [("callback_error", "error", None, 1)]
 
 
 @pytest.mark.tests_internal_exceptions