Flush logs if client/hub/sdk is closed (#3335)

Author: denrase

CHANGELOG.md

@@ -10,6 +10,7 @@
 
 - Refactor `captureReplay` and `setReplayConfig` to use FFI/JNI ([#3318](https://github.com/getsentry/sentry-dart/pull/3318))
 - Refactor `init` to use FFI/JNI ([#3324](https://github.com/getsentry/sentry-dart/pull/3324))
+- Flush logs if client/hub/sdk is closed ([#3335](https://github.com/getsentry/sentry-dart/pull/3335))
 
 ## 9.8.0
 

packages/dart/lib/src/hub.dart

@@ -399,7 +399,10 @@ class Hub {
       final item = _peek();
 
       try {
-        item.client.close();
+        final close = item.client.close();
+        if (close is Future<void>) {
+          await close;
+        }
       } catch (exception, stackTrace) {
         _options.log(
           SentryLevel.error,

packages/dart/lib/src/noop_log_batcher.dart

@@ -8,5 +8,5 @@ class NoopLogBatcher implements SentryLogBatcher {
   FutureOr<void> addLog(SentryLog log) {}
 
   @override
-  Future<void> flush() async {}
+  FutureOr<void> flush() {}
 }

packages/dart/lib/src/noop_sentry_client.dart

@@ -51,7 +51,7 @@ class NoOpSentryClient implements SentryClient {
       SentryId.empty();
 
   @override
-  Future<void> close() async {}
+  FutureOr<void> close() {}
 
   @override
   Future<SentryId> captureTransaction(

packages/dart/lib/src/sentry_client.dart

@@ -582,7 +582,11 @@ class SentryClient {
     }
   }
 
-  void close() {
+  FutureOr<void> close() {
+    final flush = _options.logBatcher.flush();
+    if (flush is Future<void>) {
+      return flush.then((_) => _options.httpClient.close());
+    }
     _options.httpClient.close();
   }
 

packages/dart/lib/src/sentry_log_batcher.dart

@@ -52,9 +52,7 @@ class SentryLogBatcher {
   }
 
   /// Flushes the buffer immediately, sending all buffered logs.
-  void flush() {
-    _performFlushLogs();
-  }
+  FutureOr<void> flush() => _performFlushLogs();
 
   void _startTimer() {
     _flushTimer = Timer(_flushTimeout, () {
@@ -66,7 +64,7 @@ class SentryLogBatcher {
     });
   }
 
-  void _performFlushLogs() {
+  FutureOr<void> _performFlushLogs() {
     // Reset timer state first
     _flushTimer?.cancel();
     _flushTimer = null;
@@ -81,17 +79,16 @@ class SentryLogBatcher {
         SentryLevel.debug,
         'SentryLogBatcher: No logs to flush.',
       );
-      return;
-    }
-
-    try {
-      final envelope = SentryEnvelope.fromLogsData(logsToSend, _options.sdk);
-      _options.transport.send(envelope);
-    } catch (error) {
-      _options.log(
-        SentryLevel.error,
-        'Failed to send batched logs: $error',
-      );
+    } else {
+      try {
+        final envelope = SentryEnvelope.fromLogsData(logsToSend, _options.sdk);
+        return _options.transport.send(envelope).then((_) => null);
+      } catch (error) {
+        _options.log(
+          SentryLevel.error,
+          'Failed to create envelope for batched logs: $error',
+        );
+      }
     }
   }
 }

packages/dart/test/mocks/mock_log_batcher.dart

@@ -13,7 +13,7 @@ class MockLogBatcher implements SentryLogBatcher {
   }
 
   @override
-  Future<void> flush() async {
+  FutureOr<void> flush() async {
     flushCalls.add(null);
   }
 }

packages/dart/test/sentry_client_test.dart

@@ -18,6 +18,9 @@ import 'package:sentry/src/transport/spotlight_http_transport.dart';
 import 'package:sentry/src/utils/iterable_utils.dart';
 import 'package:test/test.dart';
 import 'package:sentry/src/noop_log_batcher.dart';
+import 'package:sentry/src/sentry_log_batcher.dart';
+import 'package:mockito/mockito.dart';
+import 'package:http/http.dart' as http;
 
 import 'mocks.dart';
 import 'mocks/mock_client_report_recorder.dart';
@@ -2610,6 +2613,56 @@ void main() {
       await client.captureEvent(fakeEvent, stackTrace: StackTrace.current);
     });
   });
+
+  group('SentryClient close', () {
+    late Fixture fixture;
+
+    setUp(() {
+      fixture = Fixture();
+    });
+
+    test('waits for log batcher flush before closing http client', () async {
+      // Create a mock HTTP client that tracks when close is called
+      final mockHttpClient = MockHttpClient();
+      fixture.options.httpClient = mockHttpClient;
+
+      fixture.options.enableLogs = true;
+      final client = fixture.getSut();
+
+      // Create a completer to control when flush completes
+      final flushCompleter = Completer<void>();
+      bool flushStarted = false;
+
+      // Create a mock log batcher with async flush
+      final mockLogBatcher = MockLogBatcherWithAsyncFlush(
+        onFlush: () async {
+          flushStarted = true;
+          // Wait for the completer to complete
+          await flushCompleter.future;
+        },
+      );
+      fixture.options.logBatcher = mockLogBatcher;
+
+      // Start close() in the background
+      final closeFuture = client.close();
+
+      // Wait a bit longer to ensure flush has started
+      await Future.delayed(Duration(milliseconds: 50));
+
+      // Verify flush has started but HTTP client is not closed yet
+      expect(flushStarted, true, reason: 'Flush should have started');
+      verifyNever(mockHttpClient.close());
+
+      // Complete the flush
+      flushCompleter.complete();
+
+      // Wait for close to complete
+      await closeFuture;
+
+      // Now verify HTTP client was closed
+      verify(mockHttpClient.close()).called(1);
+    });
+  });
 }
 
 Future<SentryEvent> eventFromEnvelope(SentryEnvelope envelope) async {
@@ -2804,6 +2857,25 @@ class Fixture {
   }
 }
 
+class MockHttpClient extends Mock implements http.Client {}
+
+class MockLogBatcherWithAsyncFlush implements SentryLogBatcher {
+  final Future<void> Function() onFlush;
+  final addLogCalls = <SentryLog>[];
+
+  MockLogBatcherWithAsyncFlush({required this.onFlush});
+
+  @override
+  void addLog(SentryLog log) {
+    addLogCalls.add(log);
+  }
+
+  @override
+  FutureOr<void> flush() async {
+    await onFlush();
+  }
+}
+
 class ExceptionWithCause {
   ExceptionWithCause(this.cause, this.stackTrace);
 

packages/flutter/test/widgets_binding_observer_test.dart

@@ -1,6 +1,7 @@
 // ignore_for_file: invalid_use_of_internal_member
 
 import 'dart:ui';
+import 'dart:async';
 
 import 'package:flutter/foundation.dart';
 import 'package:flutter/services.dart';
@@ -603,7 +604,7 @@ class MockLogBatcher implements SentryLogBatcher {
   void addLog(SentryLog log) {}
 
   @override
-  Future<void> flush() async {
+  FutureOr<void> flush() async {
     flushCalled = true;
   }
 }