This makes me want to use Flash Builder 4!
Unit testing is relatively new to ActionScript projects. Although FlexUnit has been around for a while it wasn’t intuitive to set up and there were a lot of inconsistencies with the documentation. Lucky for us, FlexUnit is now built into Flash Builder 4. Although the documentation is still sparse, this tutorial will be a good primer for setting up a Test Suite, going over several unit test examples and showing how to run/analyze them.