Re: [PATCH 0/5] test-lib: filesystem prerequisites

Jeff King [off-list ref] writes:

That looks like a maintenance annoyance. Can't we just have the
prerequisite-checker lazily perform the test on demand and cache the
result?  It should be OK as long as:

  1. The prereq is careful about its pre- and post- conditions. We
     already make sure to clean up after those tests so as not to taint
     later tests. We would probably want to also make them more careful
     about preconditions like which directory they are in (so, for
     example, refer to "$TRASH_DIRECTORY/junk" and not "junk").

  2. The prereq test does not accidentally munge any existing test
     state from previous tests. That should not be a big deal as long as
     we avoid names like "junk" in favor of more unique names like
     "check-case-sensitivity-prereq".

Yeah, it is very desirable if we could lazy-eval, and we _should_ be
able to arrange the above.

Junio C Hamano venit, vidit, dixit 26.07.2012 22:10:

Jeff King [off-list ref] writes:

quoted

That looks like a maintenance annoyance. Can't we just have the
prerequisite-checker lazily perform the test on demand and cache the
result?  It should be OK as long as:

  1. The prereq is careful about its pre- and post- conditions. We
     already make sure to clean up after those tests so as not to taint
     later tests. We would probably want to also make them more careful
     about preconditions like which directory they are in (so, for
     example, refer to "$TRASH_DIRECTORY/junk" and not "junk").

  2. The prereq test does not accidentally munge any existing test
     state from previous tests. That should not be a big deal as long as
     we avoid names like "junk" in favor of more unique names like
     "check-case-sensitivity-prereq".

Yeah, it is very desirable if we could lazy-eval, and we _should_ be
able to arrange the above.

Yes, lazy-eval looks good and is probably easier than caching.

The adjustments to 1/5 and 4/5 look good.

5/5 needs a fix in the subject line, sorry. It should be:

t3910: use the UTF8_NFD_TO_NFC test prereq

(5/5 hasn't hit next)

Thanks,
Michael