Code-Snippets-Functions/Execute a function on a child site/WooCommerce/remove-out-of-stock-products-from-cart-checkout.txt

add_action( 'template_redirect', 'remove_oos_items_from_cart_on_cart_and_checkout' );

function remove_oos_items_from_cart_on_cart_and_checkout() {
    if ( is_admin() || ! WC()->cart || ( ! is_cart() && ! is_checkout() ) ) {
        return;
    }

    $cart = WC()->cart;
    $removed = false;

    foreach ( $cart->get_cart() as $cart_item_key => $cart_item ) {
        $product = $cart_item['data'];

        if ( ! $product->is_in_stock() ) {
            $cart->remove_cart_item( $cart_item_key );
            $removed = true;
        }
    }

    if ( $removed ) {
        wc_add_notice( __( 'Some out-of-stock products have been removed from your cart.', 'woocommerce' ), 'notice' );
    }
}