[Python-Dev] improving quality

[Neal Norwitz]

We've made a lot of improvement with testing over the years. 
Recently, we've gotten even more serious with the buildbot, Coverity,
and coverage (http://coverage.livinglogic.de).  However, in order to
improve quality even further, we need to do a little more work.  This
is especially important with the upcoming 2.5.  Python 2.5 is the most
fundamental set of changes to Python since 2.2. If we're to make this
release work, we need to be very careful about it.

In order to do the best possible job and avoid silly errors, there
shouldn't be any checkins which could change behaviour that do not
include a test.  I'm not talking about updating comments or string
constants.  But even trivial changes can cause regressions or
incompatible changes.  Just like failing tests, code checked in
without tests is fair game for being reverted if there is anything
questionable.

If you really can't figure out any way to test the change, please
describe why in your checkin message.  Just make sure it's true.  It
would be quite embarrassing to have your whole theory trashed when
Uncle Timmy comes along 5 minutes later and checks in the test you
just claimed was impossible. :-)

Cheers,
n