After product deleted customer wishlist stopped working

Question

Steps to reproduce error:

1. Create product from magento admin panel.
2. Login as customer on front end and add same product to wishlist.
3. Delete same product from admin panel.
4. For this customer, starting JS error on front side and can add any other product to wish list.

I believe same issue can be with if product contain in compare product, recently view, related product and product deleted, than product id still exist on these entity table.

Answer 1

Using a plugin, you can remove the invalid wishlist item from the collection and from the database. Create a etc/frontend/di.xml in your module (the module name is YourNamespace_Wishlist in this example):

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
    <type name="Magento\Wishlist\Model\Wishlist">
        <plugin name="yournamespace_wishlist" type="YourNamespace\Wishlist\Plugin\WishlistPlugin" />
    </type>
</config>

Then, create the plugin (Plugin/WishlistPlugin.php):

<?php
declare(strict_types=1);

namespace YourNamespace\Wishlist\Plugin;

use Magento\Framework\Exception\LocalizedException;
use Magento\Wishlist\Model\Wishlist as Subject;
use Magento\Wishlist\Model\Item as WishlistItem;
use Magento\Wishlist\Model\ResourceModel\Item as WishlistItemResource;
use Magento\Wishlist\Model\ResourceModel\Item\Collection as WishlistItemCollection;

class WishlistPlugin
{
    /**
     * @var WishlistItemResource
     */
    private $wishlistItemResourceModel;

    public function __construct(
        WishlistItemResource $wishlistItemResourceModel
    ) {
        $this->wishlistItemResourceModel = $wishlistItemResourceModel;
    }

    /**
     * Remove items without existing products from collection and from database
     *
     * @param Subject $subject
     * @param WishlistItemCollection $wishlistItemCollection
     * @return WishlistItemCollection
     *
     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
     */
    public function afterGetItemCollection(
        Subject $subject,
        WishlistItemCollection $wishlistItemCollection
    ): WishlistItemCollection {
        foreach ($wishlistItemCollection as $key => $wishlistItem) {
            /** @var WishlistItem $wishlistItem */
            try {
                $wishlistItem->getProduct();
            } catch (LocalizedException $e) {
                $wishlistItemCollection->removeItemByKey($key);
                $this->wishlistItemResourceModel->delete($wishlistItem); // phpcs:ignore MEQP1.Performance.Loop
            }
        }
        return $wishlistItemCollection;
    }
}

It's a Commerce Edition (aka Enterprise Edition) problem only - in the OpenSource edition we have a foreign key to the product entity.