Add srcSet data to Images on WooCommerce REST API response

add-srcset-to-image-data.php

<?php
/*
Plugin Name: Add SRCSET data to images
Description: Adds srcset information to WooCommerce product images in the REST API.
Version: 1.0
Author: Dago
*/

add_filter('woocommerce_rest_prepare_product_object', 'add_srcset_to_product_images', 10, 3);

function add_srcset_to_product_images($response, $product, $request) {
    $images = $response->get_data()['images'];

    foreach ($images as &$image) {
        // Get the full URL for the image
        $image_url = wp_get_attachment_url($image['id']);
        
        // Generate the srcset attribute
        $srcset = wp_get_attachment_image_srcset($image['id']);
        
        // Add the full URL and srcset to the image array
        $image['src'] = $image_url; // Ensure the 'src' is the full URL
        $image['srcset'] = $srcset; // Add the srcset attribute
    }

    // Update the images in the response
    $response->data['images'] = $images;

    return $response;
}