Redirect WooCommerce Category to Product page if it has only 1 product in it.

woo-cat-conditional-redirect.php

<?php
/* Redirect if there is only one product in the category */
add_action( 'wp_head', 'woocom_redirect_if_single_product_in_category', 10 );
function woocom_redirect_if_single_product_in_category() {
    global $wp_query;

    if (is_product_category()) {
        $cat_obj = $wp_query->get_queried_object();
        $catcount = $cat_obj->count;

        if ($catcount > 1 ){
            return;
        }

        $product = new WC_Product($wp_query->post->ID);

        if($product){
            if ( $product->is_visible() ){
                $link = get_permalink($product->post->id);
                wp_redirect($link, 302 );
                exit;
            }
        }
    }
    return false;

}