I see several questions related to testing a Magento website including "How to test Magento upgrade", which discusses manual testing.
Are there any tools for automated regression testing of my upgrade? An ideal tool would learn my products etc. from the database (or previous crawl) and make sure everything is functioning after the upgrade.
I'm sure nothing will replace manual testing for many of the extensions and for the theme/template. But a general sanity check of an automated regression test would be valueable.
I might even use the automated regression after installing any new extensions.