prefer_adjacent_string_concatenation

main.dart

void main() {
  const a1 = '';

  // Correct prefer_adjacent_string_concatenation lint.
  print(a1 + '');

  const a2 = Custom();

  // Incorrect prefer_adjacent_string_concatenation lint.
  print(a2 + '');
}

class Custom {
  const Custom();

  Custom operator +(dynamic other) => const Custom();
}