How do you approach unit testing for pluggable apps?

[Nan]

So far I usually just build a sample project that also serves as a demonstration of how to use the pluggable app, and use `manage.py test` to run the tests inside the pluggable apps test module.  Is this the preferred method?  Should a pluggable app's tests stand alone and be runnable outside of project context?  If so, how would you handle testing operations that require database access?