PHP: Get all implemented traits recursively in parents, parents-parents, parents-...-parents

implemented-traits.php

<?php declare(strict_types=1);

class SomeThing
{
    private function getClassTraitNames(string $className = null): array
    {
        if ($className === null || !class_exists($className)) {
            return [];
        }

        $ref = new ReflectionClass($className);
        $traits = [$ref->getTraitNames()];

        while ($ref) {
            $traits[] = $ref->getTraitNames();
            $ref = $ref->getParentClass();

            if (!$ref) {
                break;
            }
        }

        return array_merge(...$traits);
    }
}