getBestConstructorForCopyWith function

Implementation

ConstructorDeclaration? getBestConstructorForCopyWith(ClassDeclaration node) {
  final constructors = node.members
      .whereType<ConstructorDeclaration>()
      .toList();

  if (constructors.isEmpty) {
    return null; // Cannot generate copyWith!
  }

  // Priority 1: Unnamed constructor with named parameters
  final unnamedWithNamedParams = constructors.firstWhereOrNull((c) {
    final name = c.name?.lexeme;
    final hasNamedParams = c.parameters.parameters.any((p) => p.isNamed);
    return name == null && hasNamedParams;
  });

  if (unnamedWithNamedParams != null) {
    return unnamedWithNamedParams;
  }

  // Priority 2: Any unnamed constructor
  final unnamed = constructors.firstWhereOrNull((c) => c.name?.lexeme == null);

  if (unnamed != null) {
    return unnamed;
  }

  // Priority 3: Named constructor with most named parameters
  final bestNamed = constructors.reduce((a, b) {
    final aNamedCount = a.parameters.parameters.where((p) => p.isNamed).length;
    final bNamedCount = b.parameters.parameters.where((p) => p.isNamed).length;
    return aNamedCount >= bNamedCount ? a : b;
  });

  return bestNamed;
}