The main purpose of this utility is to test a Google Checkout API Integration level 2 implementation.

When implementing the Checkout API either using your homemade e-commerce application or an off-the-shelf one (opensource or commercial) you must be sure that everything is working properly. Therefore testing is important.

No matter how you are implementing the checkout API, when testing you will face a well known problem: confronted with the difficulties of testing synchronous and asynchronous http messages, plus 'manually' going through the Checkout UI to start testing your own end to end functional test scenarios.

A good idea would be to 'automate' as much as we can. This way we can sit and work increasing the coverage of the test cases instead of repeating manual operations.

What if we just add something between the e-commerce application and Checkout to easy the burden of manual testing integration?

This is what Mendoza is: it provides a java server that lives between a shopping cart and Google Checkout, intercepting all web services messages and using Selenium to interact automatically with the Google Checkout UI to implment test scenarios. Mendoza can be used to test shopping carts written in any languages.

More information in the wiki