Support beforeSendTransaction

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 ### Features
 
+- Support beforeSendTransaction ([#1238](https://github.com/getsentry/sentry-dart/pull/1238))
 - Add In Foreground to App context ([#1260](https://github.com/getsentry/sentry-dart/pull/1260))
 
 ### Fixes

dart/lib/src/sentry_client.dart

@@ -87,7 +87,7 @@ class SentryClient {
       return _sentryId;
     }
 
-    preparedEvent = await _processEvent(
+    preparedEvent = await _runEventProcessors(
       preparedEvent,
       eventProcessors: _options.eventProcessors,
       hint: hint,
@@ -98,27 +98,14 @@ class SentryClient {
       return _sentryId;
     }
 
-    final beforeSend = _options.beforeSend;
-    if (beforeSend != null) {
-      final beforeSendEvent = preparedEvent;
-      try {
-        preparedEvent = await beforeSend(preparedEvent, hint: hint);
-      } catch (exception, stackTrace) {
-        _options.logger(
-          SentryLevel.error,
-          'The BeforeSend callback threw an exception',
-          exception: exception,
-          stackTrace: stackTrace,
-        );
-      }
-      if (preparedEvent == null) {
-        _recordLostEvent(beforeSendEvent, DiscardReason.beforeSend);
-        _options.logger(
-          SentryLevel.debug,
-          'Event was dropped by BeforeSend callback',
-        );
-        return _sentryId;
-      }
+    preparedEvent = await _runBeforeSend(
+      preparedEvent,
+      hint: hint,
+    );
+
+    // dropped by beforeSend
+    if (preparedEvent == null) {
+      return _sentryId;
     }
 
     if (_options.platformChecker.platform.isAndroid &&
@@ -324,7 +311,7 @@ class SentryClient {
       return _sentryId;
     }
 
-    preparedTransaction = await _processEvent(
+    preparedTransaction = await _runEventProcessors(
       preparedTransaction,
       eventProcessors: _options.eventProcessors,
     ) as SentryTransaction?;
@@ -334,6 +321,14 @@ class SentryClient {
       return _sentryId;
     }
 
+    preparedTransaction =
+        await _runBeforeSend(preparedTransaction) as SentryTransaction?;
+
+    // dropped by beforeSendTransaction
+    if (preparedTransaction == null) {
+      return _sentryId;
+    }
+
     final attachments = scope?.attachments
         .where((element) => element.addToTransactions)
         .toList();
@@ -366,7 +361,44 @@ class SentryClient {
 
   void close() => _options.httpClient.close();
 
-  Future<SentryEvent?> _processEvent(
+  Future<SentryEvent?> _runBeforeSend(
+    SentryEvent event, {
+    Hint? hint,
+  }) async {
+    SentryEvent? eventOrTransaction = event;
+
+    final beforeSend = _options.beforeSend;
+    final beforeSendTransaction = _options.beforeSendTransaction;
+    String beforeSendName = 'beforeSend';
+
+    try {
+      if (event is SentryTransaction && beforeSendTransaction != null) {
+        beforeSendName = 'beforeSendTransaction';
+        eventOrTransaction = await beforeSendTransaction(event);
+      } else if (beforeSend != null) {
+        eventOrTransaction = await beforeSend(event, hint: hint);
+      }
+    } catch (exception, stackTrace) {
+      _options.logger(
+        SentryLevel.error,
+        'The $beforeSendName callback threw an exception',
+        exception: exception,
+        stackTrace: stackTrace,
+      );
+    }
+
+    if (eventOrTransaction == null) {
+      _recordLostEvent(event, DiscardReason.beforeSend);
+      _options.logger(
+        SentryLevel.debug,
+        '${event.runtimeType} was dropped by $beforeSendName callback',
+      );
+    }
+
+    return eventOrTransaction;
+  }
+
+  Future<SentryEvent?> _runEventProcessors(
     SentryEvent event, {
     Hint? hint,
     required List<EventProcessor> eventProcessors,

dart/lib/src/sentry_options.dart

@@ -150,6 +150,10 @@ class SentryOptions {
   /// object or nothing to skip reporting the event
   BeforeSendCallback? beforeSend;
 
+  /// This function is called with an SDK specific transaction object and can return a modified
+  /// transaction object or nothing to skip reporting the transaction
+  BeforeSendTransactionCallback? beforeSendTransaction;
+
   /// This function is called with an SDK specific breadcrumb object before the breadcrumb is added
   /// to the scope. When nothing is returned from the function, the breadcrumb is dropped
   BeforeBreadcrumbCallback? beforeBreadcrumb;
@@ -425,6 +429,12 @@ typedef BeforeSendCallback = FutureOr<SentryEvent?> Function(
   Hint? hint,
 });
 
+/// This function is called with an SDK specific transaction object and can return a modified transaction
+/// object or nothing to skip reporting the transaction
+typedef BeforeSendTransactionCallback = FutureOr<SentryTransaction?> Function(
+  SentryTransaction transaction,
+);
+
 /// This function is called with an SDK specific breadcrumb object before the breadcrumb is added
 /// to the scope. When nothing is returned from the function, the breadcrumb is dropped
 typedef BeforeBreadcrumbCallback = Breadcrumb? Function(

dart/test/sentry_client_test.dart

@@ -894,6 +894,74 @@ void main() {
     });
   });
 
+  group('SentryClient before send transaction', () {
+    late Fixture fixture;
+
+    setUp(() {
+      fixture = Fixture();
+    });
+
+    test('before send transaction drops event', () async {
+      final client = fixture.getSut(
+          beforeSendTransaction: beforeSendTransactionCallbackDropEvent);
+      final fakeTransaction = fixture.fakeTransaction();
+      await client.captureTransaction(fakeTransaction);
+
+      expect((fixture.transport).called(0), true);
+    });
+
+    test('async before send transaction drops event', () async {
+      final client = fixture.getSut(
+          beforeSendTransaction: asyncBeforeSendTransactionCallbackDropEvent);
+      final fakeTransaction = fixture.fakeTransaction();
+      await client.captureTransaction(fakeTransaction);
+
+      expect((fixture.transport).called(0), true);
+    });
+
+    test(
+        'before send transaction returns an transaction and transaction is captured',
+        () async {
+      final client =
+          fixture.getSut(beforeSendTransaction: beforeSendTransactionCallback);
+      final fakeTransaction = fixture.fakeTransaction();
+      await client.captureTransaction(fakeTransaction);
+
+      final capturedEnvelope = (fixture.transport).envelopes.first;
+      final transaction = await transactionFromEnvelope(capturedEnvelope);
+
+      expect(transaction['tags']!.containsKey('theme'), true);
+      expect(transaction['extra']!.containsKey('host'), true);
+      expect(transaction['sdk']!['integrations'].contains('testIntegration'),
+          true);
+      expect(
+        transaction['sdk']!['packages']
+            .any((element) => element['name'] == 'test-pkg'),
+        true,
+      );
+      expect(
+        transaction['breadcrumbs']!
+            .any((element) => element['message'] == 'processor crumb'),
+        true,
+      );
+    });
+
+    test('thrown error is handled', () async {
+      final exception = Exception("before send exception");
+      final beforeSendTransactionCallback = (SentryTransaction event) {
+        throw exception;
+      };
+
+      final client = fixture.getSut(
+          beforeSendTransaction: beforeSendTransactionCallback, debug: true);
+      final fakeTransaction = fixture.fakeTransaction();
+      await client.captureTransaction(fakeTransaction);
+
+      expect(fixture.loggedException, exception);
+      expect(fixture.loggedLevel, SentryLevel.error);
+    });
+  });
+
   group('SentryClient before send', () {
     late Fixture fixture;
 
@@ -1439,6 +1507,11 @@ FutureOr<SentryEvent?> beforeSendCallbackDropEvent(
 }) =>
     null;
 
+FutureOr<SentryTransaction?> beforeSendTransactionCallbackDropEvent(
+  SentryTransaction event,
+) =>
+    null;
+
 FutureOr<SentryEvent?> asyncBeforeSendCallbackDropEvent(
   SentryEvent event, {
   Hint? hint,
@@ -1447,6 +1520,12 @@ FutureOr<SentryEvent?> asyncBeforeSendCallbackDropEvent(
   return null;
 }
 
+FutureOr<SentryTransaction?> asyncBeforeSendTransactionCallbackDropEvent(
+    SentryEvent event) async {
+  await Future.delayed(Duration(milliseconds: 200));
+  return null;
+}
+
 FutureOr<SentryEvent?> beforeSendCallback(SentryEvent event, {Hint? hint}) {
   return event
     ..tags!.addAll({'theme': 'material'})
@@ -1458,6 +1537,16 @@ FutureOr<SentryEvent?> beforeSendCallback(SentryEvent event, {Hint? hint}) {
     ..sdk!.addPackage('test-pkg', '1.0');
 }
 
+FutureOr<SentryTransaction?> beforeSendTransactionCallback(
+    SentryTransaction transaction) {
+  return transaction
+    ..tags!.addAll({'theme': 'material'})
+    ..extra!['host'] = '0.0.0.1'
+    ..sdk!.addIntegration('testIntegration')
+    ..sdk!.addPackage('test-pkg', '1.0')
+    ..breadcrumbs!.add(Breadcrumb(message: 'processor crumb'));
+}
+
 class Fixture {
   final recorder = MockClientReportRecorder();
   final transport = MockTransport();
@@ -1477,6 +1566,7 @@ class Fixture {
     bool attachThreads = false,
     double? sampleRate,
     BeforeSendCallback? beforeSend,
+    BeforeSendTransactionCallback? beforeSendTransaction,
     EventProcessor? eventProcessor,
     bool provideMockRecorder = true,
     bool debug = false,
@@ -1494,6 +1584,7 @@ class Fixture {
     options.attachThreads = attachThreads;
     options.sampleRate = sampleRate;
     options.beforeSend = beforeSend;
+    options.beforeSendTransaction = beforeSendTransaction;
     options.debug = debug;
     options.logger = mockLogger;
 
@@ -1514,6 +1605,14 @@ class Fixture {
     return null;
   }
 
+  SentryTransaction fakeTransaction() {
+    return SentryTransaction(
+      tracer,
+      sdk: SdkVersion(name: 'sdk1', version: '1.0.0'),
+      breadcrumbs: [],
+    );
+  }
+
   void mockLogger(
     SentryLevel level,
     String message, {