The Virgo source has a a test bundle osgi-test-stubs, "OSGi Test Stubs". I have found bit of information about it, f.i. an 18 month old SpringSource blog "OSGi Test Stubs 1.0.0.M1" and passing mention on Eclipsepedia.
There appears to be only minor differences between the download from the blog and what appears to be the current source in git. I have not been able to build either with complaints of Cannot find .../virgo-build/multi-bundle/default.xml
So my questions are:
Is the test suite usable outside of the context of build Virgo?
The then how does one go about it? Is it necessary to build all of Virgo to acquire the bundle?
The OSGi test stubs are used quite a bit in the kernel, so clone the kernel repository and grep for the test stub class names in files named *Tests.java.
Note I recently upgraded the test stubs to be compatible with Equinox 3.7 which takes into account generics. If you want an earlier version compatible with OSGi 4.2, checkout the 2.1.0.RELEASE tag of the test stubs repository.