<?php declare(strict_types = 1);

namespace App\Form\Type;

use App\Form\Data\AccountData;
use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\Extension\Core\Type\PasswordType;
use Symfony\Component\Form\Extension\Core\Type\RepeatedType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\Form\FormEvent;
use Symfony\Component\Form\FormEvents;
use Symfony\Component\OptionsResolver\OptionsResolver;

class AccountType extends AbstractType
{
    public function buildForm(FormBuilderInterface $builder, array $options): void
    {
        $builder->add('password', RepeatedType::class, [
            'type' => PasswordType::class,
            'required' => false,
            'empty_data' => '', // Does not work
            'options' => [
                'empty_data' => '', // Does not work
            ],
        ]);

        // Hack: RepeatedType does not respect empty_data option
        //$builder->get('password')->addEventListener(FormEvents::SUBMIT, function (FormEvent $event): void {
        //    if (null === $event->getData()) {
        //        $event->setData('');
        //    }
        //});
    }

    public function configureOptions(OptionsResolver $resolver): void
    {
        $resolver->setDefaults([
            'data_class' => AccountData::class,
        ]);
    }
}

<?php declare(strict_types = 1);

namespace App\Form\Data;

class AccountData
{
    public string $password = '';
}