prefer-overriding-parent-equality

added in: 1.15.0

warning

Pro+

preset: recommended

Warns when a parent class implements hashCode and ==, but the child class does not implement them.

Not providing an implementation in the child class can lead to tricky bugs where equality checks don't work as expected.

Example

❌ Bad:

class SomeClass {
  @override
  int get hashCode => 1;

  @override
  bool operator ==(Object other) {
    return super == other;
  }
}

// LINT: Parent class has a custom '==' implementation. Try providing a separate implementation for this class to avoid potential mistakes.
class AnotherClass extends SomeClass {
  final String value;

  AnotherClass(this.value);
}

✅ Good:

class SomeClass {
  @override
  int get hashCode => 1;

  @override
  bool operator ==(Object other) {
    return super == other;
  }
}

class CorrectClass extends SomeClass {
  final String value;

  CorrectClass(this.value);

  @override
  int get hashCode => Object.hash(this);

  @override
  bool operator ==(Object other) {
    return other is CorrectClass && value == other.value;
  }
}