feat(dependencies): add rxdart package and improve string extension methods for better handling of empty strings and gender parsing

test/features/chat/models/chat_message_model_test.dart

@@ -0,0 +1,45 @@
+import 'package:eatvio_app/features/chat/models/chat_message_model.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  group('ChatMessageModel', () {
+    test('создает ChatMessageModel с правильными значениями', () {
+      final model = ChatMessageModel(
+        id: 1,
+        data: 'Test message',
+        mediaData: null,
+        authorId: 123,
+        updatedAt: DateTime(2024, 1, 1),
+        isRead: false,
+        isCurrentUserAuthor: true,
+        roomId: 'room-1',
+      );
+
+      expect(model.id, 1);
+      expect(model.data, 'Test message');
+      expect(model.authorId, 123);
+      expect(model.isRead, false);
+      expect(model.messageState, MessageState.sent);
+    });
+
+    test('fromJson создает ChatMessageModel из JSON', () {
+      final json = {
+        'id': 1,
+        'data': 'Test message',
+        'media_data': null,
+        'author_id': 123,
+        'updated_at': '2024-01-01T00:00:00Z',
+        'read_by_to_user': false,
+        'is_author_message_auth_user': true,
+        'room_id': 'room-1',
+      };
+
+      final model = ChatMessageModel.fromJson(json);
+
+      expect(model.id, 1);
+      expect(model.data, 'Test message');
+      expect(model.authorId, 123);
+    });
+  });
+}
+