iOS native events dropped by managed callbacks are counted twice in client reports

Part of #5634.

Branch: main. No public API change, so this doesn't need to wait for v7.

On iOS, ProcessOnBeforeSend runs the managed event processors and BeforeSend on native events:

sentry-dotnet/src/Sentry/Platforms/Cocoa/SentrySdk.cs

Lines 315 to 321 in f55e72e

    
           if (SentryEventHelper.ProcessEvent(sentryEvent, manualProcessors, null, options, DataCategory.Error) 
        
               is not { } processedEvent) 
        
           { 
        
               return null; 
        
           } 
        
           processedEvent = SentryEventHelper.DoBeforeSend(processedEvent, new SentryHint(), options);

SentryEventHelper records the drop:

sentry-dotnet/src/Sentry/Internal/SentryEventHelper.cs

Lines 26 to 60 in f55e72e

    
                       options.ClientReportRecorder.RecordDiscardedEvent(DiscardReason.CallbackError, dataCategory); 
        
                       options.LogError(e, "Event processor {0} threw an exception. The event will be dropped.", processor.GetType().Name); 
        
                       return null; 
        
                   } 
        
                   if (processedEvent == null) 
        
                   { 
        
                       options.ClientReportRecorder.RecordDiscardedEvent(DiscardReason.EventProcessor, dataCategory); 
        
                       options.LogInfo("Event dropped by processor {0}", processor.GetType().Name); 
        
                       break; 
        
                   } 
        
               } 
        
               return processedEvent; 
        
           } 
        
           public static SentryEvent? DoBeforeSend(SentryEvent? @event, SentryHint hint, SentryOptions options) 
        
           { 
        
               if (@event is null || options.BeforeSendInternal is null) 
        
               { 
        
                   return @event; 
        
               } 
        
               options.LogDebug("Calling the BeforeSend callback."); 
        
               try 
        
               { 
        
                   @event = options.BeforeSendInternal?.Invoke(@event, hint); 
        
                   if (@event == null) // Rejected event 
        
                   { 
        
                       options.ClientReportRecorder.RecordDiscardedEvent(DiscardReason.BeforeSend, DataCategory.Error); 
        
                       options.LogInfo("Event dropped by BeforeSend callback."); 
        
                   } 
        
               } 
        
               catch (Exception e) 
        
               { 
        
                   options.ClientReportRecorder.RecordDiscardedEvent(DiscardReason.CallbackError, DataCategory.Error);

.NET then returns nil, and sentry-cocoa records before_send for the same event:
https://github.com/getsentry/sentry-cocoa/blob/9.29.2/Sources/Sentry/SentryClient.m#L1164-L1172

Native event dropped because	.NET counts	sentry-cocoa counts
Event processor returns `null`	`event_processor`	`before_send`
Event processor throws	`callback_error`	`before_send`
`BeforeSend` returns `null`	`before_send`	`before_send`
`BeforeSend` throws	`callback_error`	`before_send`

Main already double-counts a null return. For a throw, the two counts also disagree on the reason.

Approach

Skip the .NET record for native events, since sentry-cocoa already counts them (decision). Until sentry-cocoa can count callback_error (getsentry/sentry-cocoa#8993), a throw on a native iOS event only shows up as before_send.

NET-843

Navigation Menu

Repository navigation

iOS native events dropped by managed callbacks are counted twice in client reports #5681

Approach

Metadata

Assignees

Labels

Projects

Milestone

Relationships

Development

	if (SentryEventHelper.ProcessEvent(sentryEvent, manualProcessors, null, options, DataCategory.Error)
	is not { } processedEvent)
	{
	return null;
	}

	processedEvent = SentryEventHelper.DoBeforeSend(processedEvent, new SentryHint(), options);

	options.ClientReportRecorder.RecordDiscardedEvent(DiscardReason.CallbackError, dataCategory);
	options.LogError(e, "Event processor {0} threw an exception. The event will be dropped.", processor.GetType().Name);
	return null;
	}

	if (processedEvent == null)
	{
	options.ClientReportRecorder.RecordDiscardedEvent(DiscardReason.EventProcessor, dataCategory);
	options.LogInfo("Event dropped by processor {0}", processor.GetType().Name);
	break;
	}
	}
	return processedEvent;
	}

	public static SentryEvent? DoBeforeSend(SentryEvent? @event, SentryHint hint, SentryOptions options)
	{
	if (@event is null \|\| options.BeforeSendInternal is null)
	{
	return @event;
	}

	options.LogDebug("Calling the BeforeSend callback.");
	try
	{
	@event = options.BeforeSendInternal?.Invoke(@event, hint);
	if (@event == null) // Rejected event
	{
	options.ClientReportRecorder.RecordDiscardedEvent(DiscardReason.BeforeSend, DataCategory.Error);
	options.LogInfo("Event dropped by BeforeSend callback.");
	}
	}
	catch (Exception e)
	{
	options.ClientReportRecorder.RecordDiscardedEvent(DiscardReason.CallbackError, DataCategory.Error);

iOS native events dropped by managed callbacks are counted twice in client reports #5681

Description

Approach

Activity

linear-code commented on Oct 7, 2026

Metadata

Metadata

Assignees

Labels

Projects

Milestone

Relationships

Development

Issue actions