Add debug diagnostics to channels integration test (#119579)

Author: goderbauer

dev/integration_tests/channels/lib/main.dart

@@ -6,6 +6,7 @@ import 'dart:async';
 import 'dart:io' show Platform;
 import 'dart:typed_data';
 
+import 'package:flutter/gestures.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_driver/driver_extension.dart';
 
@@ -16,6 +17,8 @@ import 'src/test_step.dart';
 
 void main() {
   enableFlutterDriverExtension();
+  // TODO(goderbauer): Remove this once https://github.com/flutter/flutter/issues/116663 is diagnosed.
+  debugPrintHitTestResults = true;
   runApp(const TestApp());
 }
 

packages/flutter/lib/src/gestures/binding.dart

@@ -357,15 +357,15 @@ mixin GestureBinding on BindingBase implements HitTestable, HitTestDispatcher, H
   void _handlePointerEventImmediately(PointerEvent event) {
     HitTestResult? hitTestResult;
     if (event is PointerDownEvent || event is PointerSignalEvent || event is PointerHoverEvent || event is PointerPanZoomStartEvent) {
-      assert(!_hitTests.containsKey(event.pointer), 'Pointer of $event unexpectedly has a HitTestResult associated with it.');
+      assert(!_hitTests.containsKey(event.pointer), 'Pointer of ${event.toString(minLevel: DiagnosticLevel.debug)} unexpectedly has a HitTestResult associated with it.');
       hitTestResult = HitTestResult();
       hitTest(hitTestResult, event.position);
       if (event is PointerDownEvent || event is PointerPanZoomStartEvent) {
         _hitTests[event.pointer] = hitTestResult;
       }
       assert(() {
         if (debugPrintHitTestResults) {
-          debugPrint('$event: $hitTestResult');
+          debugPrint('${event.toString(minLevel: DiagnosticLevel.debug)}: $hitTestResult');
         }
         return true;
       }());