test: add an integration test for singerdmx#2579 (singerdmx#2616)

Author: EchoEllet

example/integration_test/flutter_quill_integration_test.dart

@@ -1,8 +1,27 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_quill/flutter_quill.dart';
 import 'package:flutter_test/flutter_test.dart';
+import 'package:flutter_quill_test/flutter_quill_test.dart';
 import 'package:integration_test/integration_test.dart';
 
 void main() {
   IntegrationTestWidgetsFlutterBinding.ensureInitialized();
 
-  testWidgets('placeholder test', (tester) async {});
+  testWidgets('$QuillEditor renders and handles input without crashing',
+      (tester) async {
+    // This test ensures that the QuillEditor can be created and accepts input
+    // without crashing on any platform.
+    //
+    // Example fix: https://github.com/singerdmx/flutter-quill/pull/2579
+
+    final controller = QuillController.basic();
+    await tester.pumpWidget(MaterialApp(
+      home: QuillEditor.basic(controller: controller),
+    ));
+
+    // Simulate text input to trigger user interactions.
+    await tester.quillEnterText(find.byType(QuillEditor), 'sample text\n');
+
+    controller.dispose();
+  });
 }