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cpython/Lib/test/test_zoneinfo/test_zoneinfo_property.py
Paul Ganssle d50c37d8ad
GH-86275: Implementation of hypothesis stubs for property-based tests, with zoneinfo tests (#22863)
These are stubs to be used for adding hypothesis (https://hypothesis.readthedocs.io/en/latest/) tests to the standard library.

When the tests are run in an environment where `hypothesis` and its various dependencies are not installed, the stubs will turn any tests with examples into simple parameterized tests and any tests without examples are skipped.

It also adds hypothesis tests for the `zoneinfo` module, and a Github Actions workflow to run the hypothesis tests as a non-required CI job.

The full hypothesis interface is not stubbed out — missing stubs can be added as necessary.

Co-authored-by: Zac Hatfield-Dodds <zac.hatfield.dodds@gmail.com>
2023-05-12 08:35:53 -04:00

369 lines
12 KiB
Python

import contextlib
import datetime
import os
import pickle
import unittest
import zoneinfo
from test.support.hypothesis_helper import hypothesis
import test.test_zoneinfo._support as test_support
ZoneInfoTestBase = test_support.ZoneInfoTestBase
py_zoneinfo, c_zoneinfo = test_support.get_modules()
UTC = datetime.timezone.utc
MIN_UTC = datetime.datetime.min.replace(tzinfo=UTC)
MAX_UTC = datetime.datetime.max.replace(tzinfo=UTC)
ZERO = datetime.timedelta(0)
def _valid_keys():
"""Get available time zones, including posix/ and right/ directories."""
from importlib import resources
available_zones = sorted(zoneinfo.available_timezones())
TZPATH = zoneinfo.TZPATH
def valid_key(key):
for root in TZPATH:
key_file = os.path.join(root, key)
if os.path.exists(key_file):
return True
components = key.split("/")
package_name = ".".join(["tzdata.zoneinfo"] + components[:-1])
resource_name = components[-1]
try:
return resources.files(package_name).joinpath(resource_name).is_file()
except ModuleNotFoundError:
return False
# This relies on the fact that dictionaries maintain insertion order — for
# shrinking purposes, it is preferable to start with the standard version,
# then move to the posix/ version, then to the right/ version.
out_zones = {"": available_zones}
for prefix in ["posix", "right"]:
prefix_out = []
for key in available_zones:
prefix_key = f"{prefix}/{key}"
if valid_key(prefix_key):
prefix_out.append(prefix_key)
out_zones[prefix] = prefix_out
output = []
for keys in out_zones.values():
output.extend(keys)
return output
VALID_KEYS = _valid_keys()
if not VALID_KEYS:
raise unittest.SkipTest("No time zone data available")
def valid_keys():
return hypothesis.strategies.sampled_from(VALID_KEYS)
KEY_EXAMPLES = [
"Africa/Abidjan",
"Africa/Casablanca",
"America/Los_Angeles",
"America/Santiago",
"Asia/Tokyo",
"Australia/Sydney",
"Europe/Dublin",
"Europe/Lisbon",
"Europe/London",
"Pacific/Kiritimati",
"UTC",
]
def add_key_examples(f):
for key in KEY_EXAMPLES:
f = hypothesis.example(key)(f)
return f
class ZoneInfoTest(ZoneInfoTestBase):
module = py_zoneinfo
@hypothesis.given(key=valid_keys())
@add_key_examples
def test_str(self, key):
zi = self.klass(key)
self.assertEqual(str(zi), key)
@hypothesis.given(key=valid_keys())
@add_key_examples
def test_key(self, key):
zi = self.klass(key)
self.assertEqual(zi.key, key)
@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")
class CZoneInfoTest(ZoneInfoTest):
module = c_zoneinfo
class ZoneInfoPickleTest(ZoneInfoTestBase):
module = py_zoneinfo
def setUp(self):
with contextlib.ExitStack() as stack:
stack.enter_context(test_support.set_zoneinfo_module(self.module))
self.addCleanup(stack.pop_all().close)
super().setUp()
@hypothesis.given(key=valid_keys())
@add_key_examples
def test_pickle_unpickle_cache(self, key):
zi = self.klass(key)
pkl_str = pickle.dumps(zi)
zi_rt = pickle.loads(pkl_str)
self.assertIs(zi, zi_rt)
@hypothesis.given(key=valid_keys())
@add_key_examples
def test_pickle_unpickle_no_cache(self, key):
zi = self.klass.no_cache(key)
pkl_str = pickle.dumps(zi)
zi_rt = pickle.loads(pkl_str)
self.assertIsNot(zi, zi_rt)
self.assertEqual(str(zi), str(zi_rt))
@hypothesis.given(key=valid_keys())
@add_key_examples
def test_pickle_unpickle_cache_multiple_rounds(self, key):
"""Test that pickle/unpickle is idempotent."""
zi_0 = self.klass(key)
pkl_str_0 = pickle.dumps(zi_0)
zi_1 = pickle.loads(pkl_str_0)
pkl_str_1 = pickle.dumps(zi_1)
zi_2 = pickle.loads(pkl_str_1)
pkl_str_2 = pickle.dumps(zi_2)
self.assertEqual(pkl_str_0, pkl_str_1)
self.assertEqual(pkl_str_1, pkl_str_2)
self.assertIs(zi_0, zi_1)
self.assertIs(zi_0, zi_2)
self.assertIs(zi_1, zi_2)
@hypothesis.given(key=valid_keys())
@add_key_examples
def test_pickle_unpickle_no_cache_multiple_rounds(self, key):
"""Test that pickle/unpickle is idempotent."""
zi_cache = self.klass(key)
zi_0 = self.klass.no_cache(key)
pkl_str_0 = pickle.dumps(zi_0)
zi_1 = pickle.loads(pkl_str_0)
pkl_str_1 = pickle.dumps(zi_1)
zi_2 = pickle.loads(pkl_str_1)
pkl_str_2 = pickle.dumps(zi_2)
self.assertEqual(pkl_str_0, pkl_str_1)
self.assertEqual(pkl_str_1, pkl_str_2)
self.assertIsNot(zi_0, zi_1)
self.assertIsNot(zi_0, zi_2)
self.assertIsNot(zi_1, zi_2)
self.assertIsNot(zi_0, zi_cache)
self.assertIsNot(zi_1, zi_cache)
self.assertIsNot(zi_2, zi_cache)
class CZoneInfoPickleTest(ZoneInfoPickleTest):
module = c_zoneinfo
class ZoneInfoCacheTest(ZoneInfoTestBase):
module = py_zoneinfo
@hypothesis.given(key=valid_keys())
@add_key_examples
def test_cache(self, key):
zi_0 = self.klass(key)
zi_1 = self.klass(key)
self.assertIs(zi_0, zi_1)
@hypothesis.given(key=valid_keys())
@add_key_examples
def test_no_cache(self, key):
zi_0 = self.klass.no_cache(key)
zi_1 = self.klass.no_cache(key)
self.assertIsNot(zi_0, zi_1)
class CZoneInfoCacheTest(ZoneInfoCacheTest):
klass = c_zoneinfo.ZoneInfo
class PythonCConsistencyTest(unittest.TestCase):
"""Tests that the C and Python versions do the same thing."""
def _is_ambiguous(self, dt):
return dt.replace(fold=not dt.fold).utcoffset() == dt.utcoffset()
@hypothesis.given(dt=hypothesis.strategies.datetimes(), key=valid_keys())
@hypothesis.example(dt=datetime.datetime.min, key="America/New_York")
@hypothesis.example(dt=datetime.datetime.max, key="America/New_York")
@hypothesis.example(dt=datetime.datetime(1970, 1, 1), key="America/New_York")
@hypothesis.example(dt=datetime.datetime(2020, 1, 1), key="Europe/Paris")
@hypothesis.example(dt=datetime.datetime(2020, 6, 1), key="Europe/Paris")
def test_same_str(self, dt, key):
py_dt = dt.replace(tzinfo=py_zoneinfo.ZoneInfo(key))
c_dt = dt.replace(tzinfo=c_zoneinfo.ZoneInfo(key))
self.assertEqual(str(py_dt), str(c_dt))
@hypothesis.given(dt=hypothesis.strategies.datetimes(), key=valid_keys())
@hypothesis.example(dt=datetime.datetime(1970, 1, 1), key="America/New_York")
@hypothesis.example(dt=datetime.datetime(2020, 2, 5), key="America/New_York")
@hypothesis.example(dt=datetime.datetime(2020, 8, 12), key="America/New_York")
@hypothesis.example(dt=datetime.datetime(2040, 1, 1), key="Africa/Casablanca")
@hypothesis.example(dt=datetime.datetime(1970, 1, 1), key="Europe/Paris")
@hypothesis.example(dt=datetime.datetime(2040, 1, 1), key="Europe/Paris")
@hypothesis.example(dt=datetime.datetime.min, key="Asia/Tokyo")
@hypothesis.example(dt=datetime.datetime.max, key="Asia/Tokyo")
def test_same_offsets_and_names(self, dt, key):
py_dt = dt.replace(tzinfo=py_zoneinfo.ZoneInfo(key))
c_dt = dt.replace(tzinfo=c_zoneinfo.ZoneInfo(key))
self.assertEqual(py_dt.tzname(), c_dt.tzname())
self.assertEqual(py_dt.utcoffset(), c_dt.utcoffset())
self.assertEqual(py_dt.dst(), c_dt.dst())
@hypothesis.given(
dt=hypothesis.strategies.datetimes(timezones=hypothesis.strategies.just(UTC)),
key=valid_keys(),
)
@hypothesis.example(dt=MIN_UTC, key="Asia/Tokyo")
@hypothesis.example(dt=MAX_UTC, key="Asia/Tokyo")
@hypothesis.example(dt=MIN_UTC, key="America/New_York")
@hypothesis.example(dt=MAX_UTC, key="America/New_York")
@hypothesis.example(
dt=datetime.datetime(2006, 10, 29, 5, 15, tzinfo=UTC),
key="America/New_York",
)
def test_same_from_utc(self, dt, key):
py_zi = py_zoneinfo.ZoneInfo(key)
c_zi = c_zoneinfo.ZoneInfo(key)
# Convert to UTC: This can overflow, but we just care about consistency
py_overflow_exc = None
c_overflow_exc = None
try:
py_dt = dt.astimezone(py_zi)
except OverflowError as e:
py_overflow_exc = e
try:
c_dt = dt.astimezone(c_zi)
except OverflowError as e:
c_overflow_exc = e
if (py_overflow_exc is not None) != (c_overflow_exc is not None):
raise py_overflow_exc or c_overflow_exc # pragma: nocover
if py_overflow_exc is not None:
return # Consistently raises the same exception
# PEP 495 says that an inter-zone comparison between ambiguous
# datetimes is always False.
if py_dt != c_dt:
self.assertEqual(
self._is_ambiguous(py_dt),
self._is_ambiguous(c_dt),
(py_dt, c_dt),
)
self.assertEqual(py_dt.tzname(), c_dt.tzname())
self.assertEqual(py_dt.utcoffset(), c_dt.utcoffset())
self.assertEqual(py_dt.dst(), c_dt.dst())
@hypothesis.given(dt=hypothesis.strategies.datetimes(), key=valid_keys())
@hypothesis.example(dt=datetime.datetime.max, key="America/New_York")
@hypothesis.example(dt=datetime.datetime.min, key="America/New_York")
@hypothesis.example(dt=datetime.datetime.min, key="Asia/Tokyo")
@hypothesis.example(dt=datetime.datetime.max, key="Asia/Tokyo")
def test_same_to_utc(self, dt, key):
py_dt = dt.replace(tzinfo=py_zoneinfo.ZoneInfo(key))
c_dt = dt.replace(tzinfo=c_zoneinfo.ZoneInfo(key))
# Convert from UTC: Overflow OK if it happens in both implementations
py_overflow_exc = None
c_overflow_exc = None
try:
py_utc = py_dt.astimezone(UTC)
except OverflowError as e:
py_overflow_exc = e
try:
c_utc = c_dt.astimezone(UTC)
except OverflowError as e:
c_overflow_exc = e
if (py_overflow_exc is not None) != (c_overflow_exc is not None):
raise py_overflow_exc or c_overflow_exc # pragma: nocover
if py_overflow_exc is not None:
return # Consistently raises the same exception
self.assertEqual(py_utc, c_utc)
@hypothesis.given(key=valid_keys())
@add_key_examples
def test_cross_module_pickle(self, key):
py_zi = py_zoneinfo.ZoneInfo(key)
c_zi = c_zoneinfo.ZoneInfo(key)
with test_support.set_zoneinfo_module(py_zoneinfo):
py_pkl = pickle.dumps(py_zi)
with test_support.set_zoneinfo_module(c_zoneinfo):
c_pkl = pickle.dumps(c_zi)
with test_support.set_zoneinfo_module(c_zoneinfo):
# Python → C
py_to_c_zi = pickle.loads(py_pkl)
self.assertIs(py_to_c_zi, c_zi)
with test_support.set_zoneinfo_module(py_zoneinfo):
# C → Python
c_to_py_zi = pickle.loads(c_pkl)
self.assertIs(c_to_py_zi, py_zi)