EntityTestEntityLevelValidator.php

<?php

namespace Drupal\entity_test\Plugin\Validation\Constraint;

use Symfony\Component\Validator\Constraint;
use Symfony\Component\Validator\ConstraintValidator;

/**
 * Constraint validator for the EntityTestEntityLevel constraint.
 */
class EntityTestEntityLevelValidator extends ConstraintValidator {
    
    /**
     * {@inheritdoc}
     */
    public function validate($value, Constraint $constraint) {
        if ($value->name->value === 'entity-level-violation') {
            $this->context
                ->buildViolation($constraint->message)
                ->addViolation();
        }
        if ($value->name->value === 'entity-level-violation-with-path') {
            $this->context
                ->buildViolation($constraint->message)
                ->atPath('test.form.element')
                ->addViolation();
        }
    }

}