fluint is a pretty advanced unit testing framework build specifically for Adobe Flex solutions.

Based loosely on the concepts of FlexUnit and its ancestor JUnit, fluint provides enhanced asynchronous support, a graphical test runner, integration with continuous build systems and an optional Adobe AIR client for directory watching.

It adds support for:

• Multiple simultaneous asynchronous operations
• Asynchronous setup and teardown
• Asynchronous returns before method body completion
• Support for UIComponent testing
• Support for test sequences
• Support for testing Cairngorm commands and controllers
• XML output of testing results
• Support for externalizing tests in modules

It’s created and maintained by Digital Primates which many may know from Michael Labriola.

fluint adds some interesting features that are not covered by the basic FlexUnit framework endorsed by Adobe by both embracing basic asynchronous communications as well as direct integration testing…

Interesting stuff… check it out…
http://code.google.com/p/fluint/