class AddFileType extends AbstractType
{
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder
            ->add(
                'files',
                FileType::class,
                [
                    'multiple'       => true,
                    'error_bubbling' => true,
                ]
            );
    }

    public function configureOptions(OptionsResolver $resolver)
    {
        $resolver->setDefaults(
            [
                'required' => false,
            ]
        );
    }
}

final class AddFileCommand
{
    /**
     * @var array<UploadedFile>
     * @Assert\NotBlank(message="Veuillez sélectionner un fichier.")
     * @Assert\All({
     *     @Assert\File(
     *         maxSize = "500k",
     *         maxSizeMessage = "Custom message max size.",
     *         uploadIniSizeErrorMessage = "Custom message max size ini",
     *         uploadFormSizeErrorMessage = "Custom message max size form",
     *     )
     * })
     */
    public $files;
}