CountConstraint.php

<?php

namespace Drupal\Core\Validation\Plugin\Validation\Constraint;

use Drupal\Core\StringTranslation\TranslatableMarkup;
use Drupal\Core\Validation\Attribute\Constraint;
use Symfony\Component\Validator\Constraints\Count;

/**
 * Count constraint.
 *
 * Overrides the symfony constraint to use Drupal-style replacement patterns.
 */
class CountConstraint extends Count {
  
  /**
   * {@inheritdoc}
   */
  public function __construct(...$args) {
    $this->minMessage = 'This collection should contain %limit element or more.|This collection should contain %limit elements or more.';
    $this->maxMessage = 'This collection should contain %limit element or less.|This collection should contain %limit elements or less.';
    $this->exactMessage = 'This collection should contain exactly %limit element.|This collection should contain exactly %limit elements.';
    parent::__construct(...$args);
  }
  
  /**
   * {@inheritdoc}
   */
  public function validatedBy() : string {
    return '\\Symfony\\Component\\Validator\\Constraints\\CountValidator';
  }

}