test: add test for parse exception response

Author: 2shrestha22

packages/dart/test/src/objects/response/parse_exception_response_test.dart

@@ -0,0 +1,72 @@
+import 'dart:convert';
+
+import 'package:dio/dio.dart';
+import 'package:http/http.dart' show ClientException;
+import 'package:parse_server_sdk/parse_server_sdk.dart';
+import 'package:test/test.dart';
+
+void main() {
+  group('buildParseResponseWithException', () {
+    test('parses DioException with JSON body', () {
+      final response = Response(
+        requestOptions: RequestOptions(path: '/'),
+        data: json.encode({'error': 'some error', 'code': '123'}),
+        statusCode: 400,
+        statusMessage: 'Bad Request',
+      );
+
+      final dioException = DioException(
+        requestOptions: response.requestOptions,
+        response: response,
+      );
+
+      final result = buildParseResponseWithException(dioException);
+
+      expect(result.error, isNotNull);
+      expect(result.error!.message, 'some error');
+      expect(result.error!.code, 123);
+      expect(result.error!.exception, dioException);
+    });
+
+    test('uses statusMessage and statusCode when body is not JSON', () {
+      final response = Response(
+        requestOptions: RequestOptions(path: '/'),
+        data: 'Not a JSON body',
+        statusCode: 404,
+        statusMessage: 'Not Found',
+      );
+
+      final dioException = DioException(
+        requestOptions: response.requestOptions,
+        response: response,
+      );
+
+      final result = buildParseResponseWithException(dioException);
+
+      expect(result.error, isNotNull);
+      expect(result.error!.message, 'Not Found');
+      expect(result.error!.code, 404);
+      expect(result.error!.exception, dioException);
+    });
+
+    test('handles http ClientException', () {
+      final clientEx = ClientException('no network');
+
+      final result = buildParseResponseWithException(clientEx);
+
+      expect(result.error, isNotNull);
+      expect(result.error!.message, 'no network');
+      expect(result.error!.exception, clientEx);
+    });
+
+    test('handles generic Exception', () {
+      final ex = Exception('generic');
+
+      final result = buildParseResponseWithException(ex);
+
+      expect(result.error, isNotNull);
+      expect(result.error!.message, ex.toString());
+      expect(result.error!.exception, ex);
+    });
+  });
+}