work on test models part 1

test/model/feedback_request_test.dart

@@ -0,0 +1,58 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:tm_app/data/services/model/feedback_request/feedback_request.dart';
+
+void main() {
+  group('FeedbackRequest Tests', () {
+    test('fromJson should parse JSON correctly', () {
+      final json = {
+        'feedback_type': 'positive',
+        'tender_id': 'TND123',
+      };
+
+      final request = FeedbackRequest.fromJson(json);
+
+      expect(request.feedbackType, 'positive');
+      expect(request.tenderId, 'TND123');
+    });
+
+    test('toJson should return valid JSON map', () {
+      const request = FeedbackRequest(
+        feedbackType: 'negative',
+        tenderId: 'TND999',
+      );
+
+      final json = request.toJson();
+
+      expect(json, isA<Map<String, dynamic>>());
+      expect(json['feedback_type'], 'negative');
+      expect(json['tender_id'], 'TND999');
+    });
+
+    test('copyWith should modify specific fields only', () {
+      const request = FeedbackRequest(
+        feedbackType: 'neutral',
+        tenderId: 'TND111',
+      );
+
+      final updated = request.copyWith(
+        feedbackType: 'positive',
+      );
+
+      expect(updated.feedbackType, 'positive');
+      expect(updated.tenderId, 'TND111');
+    });
+
+    test('fromJson -> toJson round-trip should preserve data', () {
+      final json = {
+        'feedback_type': 'positive',
+        'tender_id': 'TND001',
+      };
+
+      final request = FeedbackRequest.fromJson(json);
+      final output = request.toJson();
+
+      expect(output['feedback_type'], 'positive');
+      expect(output['tender_id'], 'TND001');
+    });
+  });
+}