Проверка наличия вариации на складе (Commerce Stock)

function MODULE_check_stock(ProductVariationInterface $product) {
  $stockManager = \Drupal::service('commerce_stock.service_manager');
  $always_in_stock = $stockManager
    ->getService($product)
    ->getStockChecker()
    ->getIsAlwaysInStock($product);
  $qty = $stockManager->getStockLevel($product);
  return $always_in_stock || $qty > 0;
}