One thing to note is that you'd need to make sure if "test -e" for
example originally written really means "we want to see something
there and it does not matter if it is a file or a directory" while
turning it into test_path_exists.  The operations that such a test
follows may be expected to create a file and never a directory, in
which case the condition the original code is testing may need to
be corrected first to expect a more specific type (e.g. "test -f").
The same comment applies for the other two.

Thanks for this clarification!

Some tests check with "! test -f <path>", which often would want to
be turned into "test_path_is_missing", but you'd need to make sure
that is what the original test really meant to do.

I'd have changed them into:
-  ! test -f <path> --> ! test_path_is_file <path>
-  ! test -e <path> --> test_path_is_missing <path>
Since '! test -f <path>' and 'test_path_is_missing <path>' can return
different values.

But as you said, I'll check what they are really meant to do and
modify them accordingly :)

A microproject is not about "doing the real work to help the
project".  It is a practice session to come up with a set of small
changes and explain them well, to send the result to the list to get
reviewed, to respond to reviews and possibly send updates, and to
repeat the cycle until completion.  So most likely you'd pick a
single file or two and do the above conversion, while leaving the
others as practice material for other GSoC participants.

Enjoy.

Thanks for this clarification too. :)

Vincenzo