WPOS Sales/POS

Point-of-sale checkout logic: cart, totals, payment handling, and sale completion.

// Source: https://github.com/keya254/pharmacy-pos | License: LGPL-3.0 | Modified files must remain under LGPL-3.0
// Modifications to this file must remain under LGPL-3.0.
// Provided via justclaw.it.com; keep this notice with the code.
/**
 * sales.js is part of Wallace Point of Sale system (WPOS)
 *
 * sales.js Provides functions for processing sales, including the storage and upload of offline sales,
 * It also includes WPOSItems object for adding items to the sale.
 *
 * WallacePOS is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3.0 of the License, or (at your option) any later version.
 *
 * WallacePOS is distributed in the hope that it will be use

... (truncated -- full source via MCP)