fix: TypeError on addRelation function

[Copilot]

• Understand the issue: _TypeError (type '_Set<ParseObject>' is not a subtype of type 'Set<Contact>' in type cast) when calling addRelation with custom ParseObject subclasses
• Identify the root cause: In parse_relation.dart line 93, knownObjects = lastPreformedOperation!.value.toSet() as Set<T>; casts a Set<ParseObject> to Set<T> which fails for subclasses when getRelation<T>() was called first
• Create a failing test that reproduces the issue
• Implement the fix: Change knownObjects from Set<T> to Set<ParseObject> and remove the unsafe cast
• Verify all tests pass (28 relation tests, 157 total)
• Fix lint issues (format test file)

Original prompt

---

This section details on the original issue you should resolve

<issue_title>_TypeError on addRelation</issue_title>
<issue_description>### New Issue Checklist

• [V] I am not disclosing a vulnerability.
• [V] I am not just asking a question.
• [V] I have searched through existing issues.
• [V] I can reproduce the issue with the latest version of Parse Server and the Parse Flutter SDK.

Issue Description

Having:

Order Class

class Order extends ParseObject implements ParseCloneable {
  Order() : super(_keyTableName);
  Order.clone() : this();

  @override
  clone(Map map) => Order.clone()..fromJson(Map<String, dynamic>.from(map));

  static const String _keyTableName = 'Order';
  static const String keyInitialProduct = 'initial_product';
  static const String keyProduct = 'product';
  static const String keyPrice = 'price';
  static const String keyCertainDate = 'certain_date';
  static const String keyState = 'state';
  static const String keyAccount = 'account';


  Product? get initialProduct => get(keyInitialProduct);
  set initialProduct(Product? initialProduct) =>
      set(keyInitialProduct, initialProduct);

  Product? get product => get(keyProduct);
  set product(Product? product) => set(keyProduct, product);

  Account? get account => get(keyAccount);
  set account(Account? account) => set(keyAccount, account);

  DateTime? get certainDate => get<DateTime?>(keyCertainDate);
  set certainDate(DateTime? certainDate) =>
      set<DateTime?>(keyCertainDate, certainDate);

}

Order Schema

{
  "className": "Order",
  "fields": {
    "objectId": {
      "type": "String"
    },
    "createdAt": {
      "type": "Date"
    },
    "updatedAt": {
      "type": "Date"
    },
    "ACL": {
      "type": "ACL"
    },
    "initial_product": {
      "type": "Pointer",
      "targetClass": "Product",
      "required": false
    },
    "receivers": {
      "type": "Relation",
      "targetClass": "Contact",
      "required": false
    },
    "price": {
      "type": "Number",
      "required": false
    },
    "certain_date": {
      "type": "Date",
      "required": false
    },
    "state": {
      "type": "String",
      "required": true,
      "defaultValue": "draft"
    },
    "account": {
      "type": "Pointer",
      "targetClass": "Account",
      "required": true
    },
    "product": {
      "type": "Pointer",
      "targetClass": "Product",
      "required": false
    }
  },
  "classLevelPermissions": {
    "find": {
      "*": true
    },
    "count": {
      "*": true
    },
    "get": {
      "*": true
    },
    "create": {
      "*": true
    },
    "update": {
      "*": true
    },
    "delete": {
      "*": true
    },
    "addField": {
      "*": true
    },
    "protectedFields": {
      "*": []
    }
  },
  "indexes": {
    "_id_": {
      "_id": 1
    }
  }
}

Contact class

class Contact extends ParseObject implements ParseCloneable {
  Contact() : super(_keyTableName);
  Contact.clone() : this();

  /// Mimic a clone due to Flutter not using reflection
  @override
  clone(Map map) => Contact.clone()..fromJson(Map<String, dynamic>.from(map));

  static const String _keyTableName = 'Contact';
  static const String keyName = 'name';
  static const String keyPhone = 'phone';
  static const String keyAddress = 'address';
  static const String keyBirthday = 'birthday';
  static const String keyAccount = 'account';

  String? get name => get<String?>(keyName);
  set name(String? name) => set<String?>(keyName, name);

  String? get phone => get<String?>(keyPhone);
  set phone(String? phone) => set<String?>(keyPhone, phone);

  String? get address => get<String?>(keyAddress);
  set address(String? address) => set<String?>(keyAddress, address);

  DateTime? get birthday => get<DateTime?>(keyBirthday);
  set birthday(DateTime? birthday) => set<DateTime?>(keyBirthday, birthday);

  Account? get account => get<Account?>(keyAccount);
  set account(Account? account) => set<Account?>(keyAccount, account);

}

Steps to reproduce

      List<Contact> contactsObjects = (result as Set)
          .map((key) => Contact()..objectId = key.value)
          .toList();

      var order = widget.order!;
      order.addRelation(...

</details>

- Fixes parse-community/Parse-SDK-Flutter#999

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[parse-github-assistant]

🚀 Thanks for opening this pull request!

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 43.96%. Comparing base (76eeca4) to head (121d790).
⚠️ Report is 2 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #1098   +/-   ##
=======================================
  Coverage   43.96%   43.96%           
=======================================
  Files          61       61           
  Lines        3596     3596           
=======================================
  Hits         1581     1581           
  Misses       2015     2015           

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[mtrezza]

@copilot fix the lint issues in CI

[Copilot]

@copilot fix the lint issues in CI

Fixed in 121d790. The test file formatting has been corrected with dart format.

[parseplatformorg]

🎉 This change has been released in version dart-v9.4.6