Terry J. Reedy <tjre...@udel.edu> added the comment:
In order to understand what Paul is concretely proposing, I read and partly
reviewed his PR. I thought about maintainability.
Part A adds test.support.hypothesis_helper, similar in purpose to other
specialized xyz_helper modules. Hypothesis_helper imports either hypothesis
itself or a replacement 'as hypothesis'. The replacement is currently called
'_hypothesis_stub', but its name is irrelevant as it is normally not seen by
the user.
Part B adds a second zoneinfo test module, one that uses hypothesis. Besides
further testing zoneinfo, it serves to test hypothesis_helper and partly
justify its addition. It starts with 'from hypothesis_helper import
hypothesis. The new test module has tests such as
@hypothesis.given(
dt=hypothesis.strategies.one_of(
hypothesis.strategies.datetimes(), hypothesis.strategies.times()
)
)
@hypothesis.example(dt=datetime.datetime.min)
@hypothesis.example(dt=datetime.datetime.max)
@hypothesis.example(dt=datetime.datetime(1970, 1, 1))
@hypothesis.example(dt=datetime.datetime(2039, 1, 1))
@hypothesis.example(dt=datetime.time(0))
@hypothesis.example(dt=datetime.time(12, 0))
@hypothesis.example(dt=datetime.time(23, 59, 59, 999999))
def test_utc(self, dt):
zi = self.klass("UTC")
dt_zi = dt.replace(tzinfo=zi)
self.assertEqual(dt_zi.utcoffset(), ZERO)
self.assertEqual(dt_zi.dst(), ZERO)
self.assertEqual(dt_zi.tzname(), "UTC")
@given always (Paul?) runs the examples as subtests. When the replacement is
imported, no randomized examples are added.
If some year an example were to fail, could a hypothesis-ignorant
zoneinfo-knowing person deal with the failure? I believe so, knowing that the
above is equivalent to a test with "for dt in dt_list:\n with
self.subTest(...):\n <body of function>"
Why not require such a rewriting? Some reasons against: Rewriting by hand can
lead to errors. test_utc would have to be split into test_utc_ran(dom) and
test_utc_pre(set). Code would have to be duplicated unless factored into a
third function. For and with together add two indents, which sometimes
squeezes assert onto more lines. I believe that when hypothesis is present,
there are advantages to including preset examples with given-generated examples.
Paul would like the PR to be a 'camel's nose' in the CPython tent. This cuts
both ways. I think this PR should be judged on its own merits. Opening
possibilities can be a merit as long as not seen as pre-approval. Our CI
testing and buildbots are already configured to blame and annoy the wrong
people for random failures. I don't want more unless failure notices are sent
to someone responsible for the failing code.
----------
versions: +Python 3.9
_______________________________________
Python tracker <rep...@bugs.python.org>
<https://bugs.python.org/issue42109>
_______________________________________
_______________________________________________
Python-bugs-list mailing list
Unsubscribe:
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
