Any tips on building unit tests?

Just wondering if anyone had tips or recommendations for building unit tests for an AE effect plugin.

My main design goals are:

a) the unit test code isn't included in the release builds of the plugin

b) the unit tests run within an active AE session so they can test everything the plugin does

c) the unit test code is cross platform.

It seems like I could use some compiler directives to include/exclude any unit test logic.  And if I make the unit tests controlled/triggered by a secondary AEGP or an effect, they should be fairly easy to make cross platform.

Anyone ever try to do this?

thanks!

-Andy