test: object tests

frontend/app_flowy/packages/appflowy_editor/test/extensions/object_extension_test.dart

@@ -0,0 +1,20 @@
+import 'dart:io';
+
+import 'package:flutter/gestures.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:appflowy_editor/src/extensions/object_extensions.dart';
+
+void main() {
+  group('FlowyObjectExtensions::', () {
+    test('unwrapOrNull', () {
+      final result = const TextSpan().unwrapOrNull<HitTestTarget>();
+      assert(result is TextSpan);
+    });
+
+    test('unwrapOrNull - return null', () {
+      final result = const TextSpan().unwrapOrNull<ServerSocket>();
+      expect(result, null);
+    });
+  });
+}