BizUnit is a great tool for performing end-to-end testing of BizTalk applications (and can even be used for testing non-BizTalk applications like Web services too).
Although you're not strictly performing unit-testing of your BizTalk artefacts per-se, with the right setup you can get very close to unit testing.
For example if you want to test an orchestration in isolation you can:
- Hook your orchestration up to file send/receive ports
- Write a façade orchestration which calls your orchestration, and is itself hooked up to file send/receive ports or
- Write your own orchestration hosting engine
I don't know many people who'd be crazy enough to do 3) (although I do know one…) but BizUnit is of great help for 1) and 2)
In its simplest form you can use BizUnit to[...]