WooCommerce rss2_item action - add blog posts featured images to RSS feed

add_rss_featured_image.php

<?php
//https://codex.wordpress.org/Plugin_API/Action_Reference/rss2_item
//https://validator.w3.org/feed/
function add_rss_featured_image() {
    global $post;

    if(has_post_thumbnail($post->ID)) {
        $thumbnail_id = get_post_thumbnail_id($post->ID);
        $thumbnail = wp_get_attachment_image_src($thumbnail_id, 'large');

	$output = sprintf('<media:content xmlns:media="http://search.yahoo.com/mrss/" medium="image" type="%1$s" url="%2$s" width="%3$s" height="%4$s" />',
		get_post_mime_type($thumbnail_id),
		esc_url($thumbnail[0]),
		$thumbnail[1],
		$thumbnail[2]);

	echo $output;
    }
}

add_action('rss2_item', 'add_rss_featured_image');