isAvailable() and isSalable() return false for all products on frontend even though they are definitely saleable

Question

I just completed a migration from M1 to M2 version 2.3.5-p1.

All of the product and stock data was correctly migrated (I can see it in the database) but no matter what I do, products are all showing as "Out of Stock" on the frontend product pages.

This seems to be because the $_product->isAvailable() check always returns false in the file vendor/magento/module-catalog/view/frontend/templates/product/view/type/default.phtml.

However I triple checked all the product and inventory data in the database and everything (stock, associated products, etc.) are definitely correct for my products.

I have done all the usual: re-indexing, clearing cache, deleting folders, etc. etc.

I even made a quick external script to check the products were salable programatically, and they are:

<?php

// ---------------------
// Config
// ---------------------
$sku     = "SOMESKU123";
$storeId = 1;
// ---------------------

// Get Object Manager
require __DIR__ . "/../app/bootstrap.php";
\Magento\Framework\App\Bootstrap::create(BP, $_SERVER);
$objectManager = \Magento\Framework\App\ObjectManager::getInstance();

// Set Magento area to frontend
$objectManager->get("Magento\Framework\App\State")->setAreaCode("frontend");

// Ensure correct store view is set
$storeManager = $objectManager->get("Magento\Store\Model\StoreManagerInterface");
$storeManager->setCurrentStore($storeId);

// Get product data
$myHelper = $objectManager->get("MyModule\MyFunctions\Helper\Data");
$product  = $objectManager->get("\Magento\Catalog\Model\ProductFactory")->create()->loadByAttribute("sku", $sku);

echo "\n Magento area code: " . $objectManager->get("\Magento\Framework\App\State")->getAreaCode();
echo "\n Product Name: "      . $product->getName();
echo "\n isSalable: "         . $product->isSalable();
echo "\n isAvailable: "       . $product->isAvailable();
echo "\n isInStock: "         . $product->isInStock();

The output of the above script when I run it on the same Magento 2 instance:

Area code: frontend
Name: Whatever Product
isSalable: 1
isAvailable: 1
isInStock: 1

But when I load the same product on the "real" Magento 2 frontend, it shows as Out of Stock and isAvailable() returns false.

Why would this happen?

Update

I've done more debugging. It turns out there are many files involved in displaying the stock status on the product page:

vendor\magento\module-catalog\view\frontend\templates\product\view\type\default.phtml
vendor\magento\module-catalog\Model\Product.php
vendor\magento\module-configurable-product\Model\Product\Type\Configurable.php
vendor\magento\module-catalog\Model\Product\Type\AbstractType.php
vendor\magento\module-catalog\Model\ProductRender.php
vendor\magento\module-catalog-inventory\Observer\AddInventoryDataObserver.php
vendor\magento\module-catalog-inventory\Helper\Stock.php
vendor\magento\module-catalog-inventory\Model\StockRegistryStorage.php
vendor\magento\module-inventory-catalog\Plugin\CatalogInventory\Helper\Stock\AdaptAssignStatusToProductPlugin.php
vendor\magento\module-inventory-catalog\etc\di.xml
vendor\magento\framework\Interception\Interceptor.php
vendor\magento\module-inventory-catalog\Plugin\InventorySalesApi\StockResolver\AdaptStockResolverToAdminWebsitePlugin.php
vendor\magento\module-inventory-configurable-product\etc\frontend\di.xml

However, I believe the problem is related to the assignStatusToProduct function, which is expanded upon by the aroundAssignStatusToProduct function inside vendor/magento/module-inventory-catalog/Plugin/CatalogInventory/Helper/Stock/AdaptAssignStatusToProductPlugin.php.

If I modify framework/Interception/Interceptor.php and add a hack to effectively skip the above plugin, the stock status starts to appear normally:

public function ___callParent($method, array $arguments)
{
    // Begin hack
    if ($method == "assignStatusToProduct") {
        return;
    }
    // End hack

    return parent::$method(...array_values($arguments));
}

Obviously this is not a real solution. I don't fully understand why this plugin or function would result in an incorrect stock status, but from what I've read it might be related to 2.3's new Multi Source Inventory functionality so I will try disabling those inventory modules next and see what happens.

Also, this is a wild guess, but the reason this issue only happens on the Magento frontend (and not via my PHP script above) might be because this function is inserted via dependency injection (module-inventory-catalog\etc\di.xml) which might not be injected when I call ObjectManager directly in my script.

Any suggestions are appreciated.

Answer 1

I'm posting this as an answer even though it's not the answer, but rather a workaround.

Looks like Multi Source Inventory, introduced in Magento 2.3, causes the issue. You can see details of my debugging attempts in my question update, above, but in summary: disabling the MSI modules stopped the issue.

I disabled them using a command from this answer:

php bin/magento module:status | grep Magento_Inventory | grep -v List | grep -v None | grep -v -e '^$' | xargs php bin/magento module:disable

After doing this (and setup:upgrade etc.) the products show normally.

Interestingly, Magento's official documentation suggests ...you may need to disable Inventory Management modules to speed up the upgrade process for merchants migrating....

I didn't investigate further because I'm happy to disable MSI, but I suspect the root cause is either:

• Perhaps my products weren't correctly assigned to a MSI stock source; or
• Perhaps a default source didn't exist at all (you can check via Stores > Inventory > Source); or
• Perhaps MSI doesn't like the way my products were configured (configurable SKU with Manage Stock: Yes, Stock Status: In Stock, Qty: 0 plus associated child products with positive quantities).
• Perhaps there's a bug in MSI (all I know is that isSalable was being set to 0 in the aroundAssignStatusToProduct plugin as I mention in the OP)

The following also helped me:

• Disabling the Magento MSI (Archived)
• Getting the product stock status programatically in Magento 2 with and without MSI (Archived)

Answer 2

I am assuming this is related to multi-source inventory that has been added to the recent Magento version, to check if your product has been assigned to multisource inventory correctly you can go to the backend and have a look at this.

you can check by disabling the multisource inventory to check if that solves your issue, you can always enable it if it does not.

php bin/magento module:disable –f Magento_Inventory Magento_InventoryAdminUi Magento_InventoryApi Magento_InventoryBundleProduct Magento_InventoryBundleProductAdminUi Magento_InventoryCatalog Magento_InventorySales Magento_InventoryCatalogAdminUi Magento_InventoryCatalogApi Magento_InventoryCatalogSearch Magento_InventoryConfigurableProduct Magento_InventoryConfigurableProductAdminUi Magento_InventoryConfigurableProductIndexer Magento_InventoryConfiguration Magento_InventoryConfigurationApi Magento_InventoryGroupedProduct Magento_InventoryGroupedProductAdminUi Magento_InventoryGroupedProductIndexer Magento_InventoryImportExport Magento_InventoryIndexer Magento_InventoryLowQuantityNotification Magento_InventoryLowQuantityNotificationAdminUi Magento_InventoryLowQuantityNotificationApi Magento_InventoryMultiDimensionalIndexerApi Magento_InventoryProductAlert Magento_InventoryReservations Magento_InventoryReservationsApi Magento_InventoryCache Magento_InventorySalesAdminUi Magento_InventorySalesApi Magento_InventorySalesFrontendUi Magento_InventoryShipping Magento_InventorySourceDeductionApi Magento_InventorySourceSelection Magento_InventorySourceSelectionApi Magento_InventoryShippingAdminUi Magento_InventoryDistanceBasedSourceSelectionAdminUi Magento_InventoryDistanceBasedSourceSelectionApi Magento_InventoryElasticsearch Magento_InventoryExportStockApi Magento_InventoryReservationCli Magento_InventoryExportStock Magento_InventorySetupFixtureGenerator Magento_InventoryDistanceBasedSourceSelection

you can get more information about disabling it from here link

or you can assign your products to multisource inventory using the below code this will be needed to do for all products

  $product_id = $product->getIdBySku("pbnddee");
  $_sourceItemsSaveInterface = $objectManager->get('Magento\InventoryApi\Api\SourceItemsSaveInterface');
  $_sourceItemFactory = $objectManager->create('Magento\InventoryApi\Api\Data\SourceItemInterfaceFactory');
  $sourceItem = $_sourceItemFactory->create();
  $sourceItem->setSourceCode("default");
  $sourceItem->setSku(pbnddee);
  $sourceItem->setQuantity(10);
  $sourceItem->setStatus(1);
  $_sourceItemsSaveInterface->execute([$sourceItem]);

hope my answer would help