1. I wonder if there is an IMP_WARN macro that would output some message
under some condition, just like IMP_USAGE_CHECK() does but without
aborting the application
Yes; it is called IMP_WARN. ;) See kernel/include/log.h.
2. I would like to write test case functions
a. Is there a doc on how to write good test functions ?
There are many guides to writing good unit tests. One good introduction
is in Dive Into Python at