Before we release a new version of the Maps API, we always run it through a huge bank of tests to make sure standard functionality is working. But one thing we've realized since releasing the Maps API and watching its adoption is that it can be used in ways that we never imagined - and subsequently, ways we never thought to test.
So we figured the best solution would just be to let you, the creative developers, tell us exactly what functionality you want tested - by adding your own tests. We've open sourced our integration tests and are now ready to accept contributions. Our infrastructure allows us to run these tests on the stable, current, and bleeding edge versions of the API, so that potential problems can be discovered long before they are out in the wild.
The tests we have released use Selenium. Selenium is an open source tool for automating tests of human-browser interaction. It runs in a range of browsers, so by its very nature it takes into account browser discrepancies. As an added benefit, developers can run tests by simply going to a url and clicking a 'run' button!
The screenshot below shows our basic test running (and passing, whee!):
Note that we have hundreds of non-Selenium unit tests for expected functionality, but we're not releasing those just yet as they're more tightly coupled with Google infrastructure.
For information on running and contributing tests, read the project wiki. Thanks for reading, and we look forward to your contributions.