title: How can I test-drive IOKit userspace driver development?
body: <p>I'm about to attempt to write a USB driver for my application on OS X using IOKit.  I've opted for the userspace route rather than developing a kext since it's so much easier to debug etc, but I'm having trouble working out how I  could possibly test-drive my development.</p>
  
  <p>If possible, I'd like to find a way to insert a fake USB device into the IOKit registry and have my unit-tests ensure that my driver code reacts to the various notifications in the correct manner.  My initial research hasn't turned up much but it doesn't seem like there is any way I could create such a mock device from userspace, which would in turn mean I would have to write a kext specifically do drive my tests: clearly this is far from ideal because I'm then back to contending with all the problems that go with developing at that level.</p>
  
  <p>Does anyone have any experience test-driving this kind of driver development on OS X? </p>