fix(ttfd): unfinished ttfd should match ttid duration

CHANGELOG.md

@@ -64,6 +64,7 @@ Navigator.push(
 - iOS replay integration when only `onErrorSampleRate` is specified ([#2306](https://github.com/getsentry/sentry-dart/pull/2306))
 - Fix TTID timing issue ([#2326](https://github.com/getsentry/sentry-dart/pull/2326))
 - Start missing TTFD for root screen transaction ([#2332](https://github.com/getsentry/sentry-dart/pull/2332))
+- Match TTFD to TTID end timespan if TTFD is unfinished when user navigates to another screen ([#2347](https://github.com/getsentry/sentry-dart/pull/2347))
 - Accessing invalid json fields from `fetchNativeAppStart` should return null ([#2340](https://github.com/getsentry/sentry-dart/pull/2340))
 - Error when calling `SentryFlutter.reportFullyDisplayed()` twice ([#2339](https://github.com/getsentry/sentry-dart/pull/2339))
 

flutter/lib/src/navigation/sentry_navigator_observer.dart

@@ -8,6 +8,7 @@ import 'package:meta/meta.dart';
 import '../native/native_frames.dart';
 import '../native/sentry_native_binding.dart';
 import 'time_to_display_tracker.dart';
+import 'time_to_full_display_tracker.dart';
 
 import '../../sentry_flutter.dart';
 import '../event_processor/flutter_enricher_event_processor.dart';
@@ -309,13 +310,18 @@ class SentryNavigatorObserver extends RouteObserver<PageRoute<dynamic>> {
       // Cancel unfinished TTID/TTFD spans, e.g this might happen if the user navigates
       // away from the current route before TTFD or TTID is finished.
       for (final child in (transaction as SentryTracer).children) {
+        if (child.finished) continue;
+
         final isTTIDSpan = child.context.operation ==
             SentrySpanOperations.uiTimeToInitialDisplay;
         final isTTFDSpan =
             child.context.operation == SentrySpanOperations.uiTimeToFullDisplay;
-        if (!child.finished && (isTTIDSpan || isTTFDSpan)) {
+        if (isTTIDSpan || isTTFDSpan) {
+          final finishTimestamp = isTTFDSpan
+              ? (ttidEndTimestampProvider() ?? endTimestamp)
+              : endTimestamp;
           await child.finish(
-            endTimestamp: endTimestamp,
+            endTimestamp: finishTimestamp,
             status: SpanStatus.deadlineExceeded(),
           );
         }

flutter/lib/src/navigation/time_to_full_display_tracker.dart

@@ -35,7 +35,7 @@ class TimeToFullDisplayTracker {
   final options = Sentry.currentHub.options;
 
   // End timestamp provider is only needed when the TTFD timeout is triggered
-  EndTimestampProvider _endTimestampProvider = ttidEndTimestampProvider();
+  EndTimestampProvider _endTimestampProvider = ttidEndTimestampProvider;
   Completer<void> _completedTTFDTracking = Completer<void>();
 
   Future<void> track({
@@ -115,5 +115,5 @@ class TimeToFullDisplayTracker {
 typedef EndTimestampProvider = DateTime? Function();
 
 @internal
-EndTimestampProvider ttidEndTimestampProvider() =>
+EndTimestampProvider ttidEndTimestampProvider =
     () => TimeToInitialDisplayTracker().endTimestamp;

flutter/test/navigation/time_to_display_tracker_test.dart

@@ -198,7 +198,7 @@ class Fixture {
   final options = defaultTestOptions()
     ..dsn = fakeDsn
     ..tracesSampleRate = 1.0;
-  late final endTimeProvider = ttidEndTimestampProvider();
+  late final endTimeProvider = ttidEndTimestampProvider;
   late final hub = Hub(options);
 
   TimeToInitialDisplayTracker? ttidTracker;

flutter/test/sentry_navigator_observer_test.dart

@@ -380,6 +380,83 @@ void main() {
           .called(1);
     });
 
+    // e.g when a user navigates to another screen before ttfd or ttid is finished
+    test('cancelled TTID and TTFD spans do not add measurements', () async {
+      final initialRoute = route(RouteSettings(name: 'Initial Route'));
+      final newRoute = route(RouteSettings(name: 'New Route'));
+
+      final hub = _MockHub();
+      final transaction = getMockSentryTracer(finished: false) as SentryTracer;
+
+      final mockChildTTID = MockSentrySpan();
+      final mockChildTTFD = MockSentrySpan();
+
+      when(transaction.children).thenReturn([
+        mockChildTTID,
+        mockChildTTFD,
+      ]);
+
+      when(transaction.measurements).thenReturn(<String, SentryMeasurement>{});
+
+      when(mockChildTTID.finished).thenReturn(false);
+      when(mockChildTTID.context).thenReturn(SentrySpanContext(
+          operation: SentrySpanOperations.uiTimeToInitialDisplay));
+      when(mockChildTTID.status).thenReturn(SpanStatus.cancelled());
+
+      when(mockChildTTFD.finished).thenReturn(false);
+      when(mockChildTTFD.context).thenReturn(SentrySpanContext(
+          operation: SentrySpanOperations.uiTimeToFullDisplay));
+      when(mockChildTTFD.status).thenReturn(SpanStatus.cancelled());
+
+      when(transaction.context)
+          .thenReturn(SentrySpanContext(operation: 'navigation'));
+      when(transaction.status).thenReturn(null);
+      when(transaction.finished).thenReturn(false);
+
+      when(transaction.startChild(
+        'ui.load.initial_display',
+        description: anyNamed('description'),
+        startTimestamp: anyNamed('startTimestamp'),
+      )).thenReturn(MockSentrySpan());
+
+      when(hub.getSpan()).thenReturn(transaction);
+      when(hub.startTransactionWithContext(
+        any,
+        startTimestamp: anyNamed('startTimestamp'),
+        waitForChildren: true,
+        autoFinishAfter: anyNamed('autoFinishAfter'),
+        trimEnd: true,
+        onFinish: anyNamed('onFinish'),
+      )).thenReturn(transaction);
+
+      final sut =
+          fixture.getSut(hub: hub, autoFinishAfter: Duration(seconds: 5));
+
+      // Simulate pushing the initial route
+      sut.didPush(initialRoute, null);
+
+      // Simulate navigating to a new route before TTID and TTFD spans finish
+      sut.didPush(newRoute, initialRoute);
+
+      // Allow async operations to complete
+      await Future<void>.delayed(const Duration(milliseconds: 100));
+
+      // Verify that the TTID and TTFD spans are finished with a cancelled status
+      verify(mockChildTTID.finish(
+              endTimestamp: anyNamed('endTimestamp'),
+              status: SpanStatus.deadlineExceeded()))
+          .called(1);
+      verify(mockChildTTFD.finish(
+              endTimestamp: anyNamed('endTimestamp'),
+              status: SpanStatus.deadlineExceeded()))
+          .called(1);
+
+      // Verify that the measurements are not added to the transaction
+      final measurements = transaction.measurements;
+      expect(measurements.containsKey('time_to_initial_display'), isFalse);
+      expect(measurements.containsKey('time_to_full_display'), isFalse);
+    });
+
     test(
         'unfinished children will be finished with deadline_exceeded on didPush',
         () async {
@@ -409,10 +486,7 @@ void main() {
 
       final sut = fixture.getSut(hub: hub);
 
-      // Push to new screen, e.g app start / root screen
       sut.didPush(currentRoute, null);
-
-      // Push to screen e.g root to user screen
       sut.didPush(currentRoute, null);
 
       await Future<void>.delayed(const Duration(milliseconds: 100));