Issue #3120117 by Neograph734, jsacksick: ProductVariationFieldRenderer's...

   */

  protected function prepareForAjax(array $rendered_field, $field_name, ProductVariationInterface $variation) {

    $ajax_class = $this->buildAjaxReplacementClass($field_name, $variation);

    // Lazy built fields cannot have attributes, but we cannot change the order

    // of the render array either, because that breaks templates. For now, only

    // wrap lazy built fields in an additional container.

    // See https://www.drupal.org/project/commerce/issues/3120117.

    if (isset($rendered_field['#lazy_builder'])) {

      $rendered_field = [

        '#type' => 'container',

        '#weight' => $rendered_field['#weight'],

        '#attributes' => ['class' => [$ajax_class]],

        '#ajax_replace_class' => $ajax_class,

        'rendered_field' => $rendered_field,

      ];

    }

    else {

      $rendered_field['#attributes']['class'][] = $ajax_class;

      $rendered_field['#ajax_replace_class'] = $ajax_class;

      // If this renders a view, we can return here. Views have no visible

      // children and will have its type replaced by 'container' otherwise.

      if (isset($rendered_field['#type']) && $rendered_field['#type'] == 'view') {

        return $rendered_field;

      }

      // Ensure that a <div> is rendered even if the field is empty, to allow

      // field replacement to work when the variation changes.

      if (!Element::children($rendered_field)) {

        $rendered_field['#type'] = 'container';

      }

    }

    return $rendered_field;

  }