Try following way:
app/code/SR/Stackexchange/etc/frontend/di.xml
<?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\ConfigurableProduct\Block\Product\View\Type\Configurable">
<plugin name="sr_configurable_product_configurable" type="SR\Stackexchange\Plugin\Block\ConfigurableProduct\Product\View\Type\Configurable" sortOrder="1"/>
</type>
</config>
app/code/SR/Stackexchange/Plugin/Block/ConfigurableProduct/Product/View/Type/Configurable.php
<?php
namespace SR\Stackexchange\Plugin\Block\ConfigurableProduct\Product\View\Type;
use Magento\Framework\Json\EncoderInterface;
use Magento\Framework\Json\DecoderInterface;
class Configurable
{
/**
* @var EncoderInterface
*/
protected $jsonEncoder;
/**
* @var DecoderInterface
*/
protected $jsonDecoder;
/**
* @var \Magento\CatalogInventory\Api\StockRegistryInterface
*/
protected $stockRegistry;
/**
* Configurable constructor.
*
* @param EncoderInterface $jsonEncoder
* @param DecoderInterface $jsonDecoder
* @param \Magento\CatalogInventory\Api\StockRegistryInterface $stockRegistry
*/
public function __construct(
EncoderInterface $jsonEncoder,
DecoderInterface $jsonDecoder,
\Magento\CatalogInventory\Api\StockRegistryInterface $stockRegistry
) {
$this->jsonDecoder = $jsonDecoder;
$this->jsonEncoder = $jsonEncoder;;
$this->stockRegistry = $stockRegistry;
}
public function aroundGetJsonConfig(
\Magento\ConfigurableProduct\Block\Product\View\Type\Configurable $subject,
\Closure $proceed
) {
$config = $proceed();
$config = $this->jsonDecoder->decode($config);
$productsCollection = $subject->getAllowProducts();
$stockInfo = array();
foreach ($productsCollection as $product) {
$productId = $product->getId();
$stockItem = $this->stockRegistry->getStockItem($product->getId());
if ($stockItem->getQty() getIsInStock())) {
$stockInfo[$productId] = array(
"stockLabel" => __('Out of stock'),
"stockQty" => intval($stockItem->getQty()),
"is_in_stock" => false
);
} else {
$stockInfo[$productId] = array(
"stockLabel" => __('In Stock'),
"stockQty" => intval($stockItem->getQty()),
"is_in_stock" => true
);
}
}
$config['stockInfo'] = $stockInfo;
return $this->jsonEncoder->encode($config);
}
}
