? not at all -- you make the deletion of the directory dependent on whether or not you tested true for the directory being present. I don't see why this would cause any race condition...

The race condition is when another program is interacting with that directory too. So you check that the directory exists, and then the other program gets CPU time and uses it to delete that directory, and then your program tries to delete that directory but fails.

To avoid this, you have to either get a lock on that directory somehow (opening a transaction), or you have to try deleting the directory and then check the return code or catch any exceptions to tell whether the directory existed at the time of the attempted deletion.

It does, because somebody might have done something to the filesystem between your test and the rest of your code.

This is why I found your "Defensive Programming 101 really" comment slightly arrogant (perhaps I misunderstood the intention). Writing correct programs is not easy and one should not mock others, because there is always something new to learn.