Stop add to cart based on rules

[I apparently just made a commit via a comment? Someone please remove that.]

I'm a little late to this party, but if anyone else has this issue, here's some code I wrote to remove a line item from an order. Use this with the "After saving a new commerce line item" event. I wish you could prevent it being added on presave but the requisite data isn't available at that time.

function wrltweaks_rules_action_info() {
  return [
    'wrltweaks_remove_line_item_from_order' => [
      'label' => t('Remove item from order'),
      'group' => t('Commerce Line Item'),
      'parameter' => [
        'commerce_line_item' => [
          'type' => 'commerce_line_item',
          'label' => t('Line item'),
        ],
        'commerce_order' => [
          'type' => 'commerce_order',
          'label' => t('Order'),
        ],
      ],
    ],
  ];
}

function wrltweaks_remove_line_item_from_order($lineItem, $order) {
  $lineItemId = $lineItem->line_item_id;
  commerce_cart_order_product_line_item_delete($order, $lineItemId, TRUE);
}