WooCommerce - Add a low stock note to cart items

gistfile1.txt

add_filter( 'woocommerce_cart_item_name', 'cart_low_stock_note', 10, 3 );

function cart_low_stock_note( $title, $cart_item, $cart_item_key ) {
  	if( $cart_item ) {
    	$_product = apply_filters( 'woocommerce_cart_item_product', $cart_item['data'], $cart_item, $cart_item_key );
    	$output = '';
    	$output.= $title;
    	
    	// threshold
    	if( $_product->get_stock_quantity() <= 4 ) { 
      		$output.= '<p class="stock-note">' . sprintf( __( 'Note: Only %d left in stock', 'woocommerce' ), $_product->get_stock_quantity() ) .'</p>';
    	}

    	return $output;
	}
}