ERP5Type.tests.utils: introduce timeZoneContext

This is a context manager which temporary allow to change the time zone.

It is not thread safe and intended to be used in tests only, to replace
setTimeZoneToUTC and setTimezone methods by something unified which
makes the transition to DateTime 4 easier, because changing timezone
was done by patching private attributes and the DateTime 4 use different
attributes.

bt5/erp5_core_test/TestTemplateItem/portal_components/test.erp5.testDateUtils.py

@@ -27,12 +27,15 @@
 #
 ##############################################################################
 
+import os
 import unittest
 
 from DateTime import DateTime
 from erp5.component.module.DateUtils import addToDate, getIntervalListBetweenDates, \
     atTheEndOfPeriod, getClosestDate
 from Products.ERP5Type.tests.ERP5TypeTestCase import ERP5TypeTestCase
+from Products.ERP5Type.tests.utils import timeZoneContext
+
 
 class TestDateUtils(unittest.TestCase):
   """
@@ -199,8 +202,51 @@ class TestPinDateTime(ERP5TypeTestCase):
     self.assertGreaterEqual(DateTime(), actual_begin_date)
 
 
+class TestTimeZoneContext(ERP5TypeTestCase):
+  def afterSetUp(self):
+    self.reference_date_in_utc = DateTime('2001/02/03 00:00:00 UTC')
+    self.actual_timezone = DateTime().timezone()
+    self.actual_environ_tz = os.environ.get('TZ')
+
+  def test_timezone_context_UTC(self):
+    with timeZoneContext('UTC'):
+      self.assertEqual(DateTime().timezone(), 'UTC')
+      self.assertEqual(
+        DateTime(2001, 2, 3).toZone('UTC'), self.reference_date_in_utc)
+    self.assertEqual(DateTime().timezone(), self.actual_timezone)
+    self.assertEqual(os.environ.get('TZ'), self.actual_environ_tz)
+
+  def test_timezone_context_with_dst(self):
+    with timeZoneContext('Europe/Paris'):
+      self.assertEqual(DateTime(2021, 2, 1).timezone(), 'CET')
+      self.assertEqual(DateTime(2021, 7, 1).timezone(), 'CEST')
+      self.assertEqual(
+        DateTime(2001, 2, 3, 1, 0, 0).toZone('UTC'),
+        self.reference_date_in_utc)
+    self.assertEqual(DateTime().timezone(), self.actual_timezone)
+    self.assertEqual(os.environ.get('TZ'), self.actual_environ_tz)
+
+  def test_timezone_context_without_dst(self):
+    with timeZoneContext('Asia/Tokyo'):
+      self.assertEqual(DateTime().timezone(), 'JST')
+      self.assertEqual(
+        DateTime(2001, 2, 3, 9, 0, 0).toZone('UTC'), self.reference_date_in_utc)
+    self.assertEqual(DateTime().timezone(), self.actual_timezone)
+    self.assertEqual(os.environ.get('TZ'), self.actual_environ_tz)
+
+  def test_timezone_abbreviation(self):
+    with timeZoneContext('GMT-7'):
+      self.assertEqual(DateTime(2021, 2, 1).timezone(), 'GMT-7')
+      self.assertEqual(DateTime(2021, 7, 1).timezone(), 'GMT-7')
+      self.assertEqual(
+        DateTime(2001, 2, 2, 17, 0, 0).toZone('UTC'), self.reference_date_in_utc)
+    self.assertEqual(DateTime().timezone(), self.actual_timezone)
+    self.assertEqual(os.environ.get('TZ'), self.actual_environ_tz)
+
+
 def test_suite():
   suite = unittest.TestSuite()
   suite.addTest(unittest.makeSuite(TestDateUtils))
   suite.addTest(unittest.makeSuite(TestPinDateTime))
+  suite.addTest(unittest.makeSuite(TestTimeZoneContext))
   return suite

bt5/erp5_web_renderjs_ui_test/ExtensionTemplateItem/portal_components/extension.erp5.WebRenderJSTestUtils.py

-import os, time
-from DateTime import DateTime
+from Products.ERP5Type.tests.utils import timeZoneContext
+
+current_timezone_contexts = []
 
 def setTimezone(timezone):
-  # timezone must be for example GMT-7
-  os.environ['TZ'] = timezone
-  time.tzset()
-  DateTime._isDST = False
-  DateTime._localzone = DateTime._localzone0 = DateTime._localzone1 = timezone
+  """Change the default timezone to `timezone`.
+  """
+  if current_timezone_contexts:
+    resetTimeZone()
+
+  tzc = timeZoneContext(timezone)
+  tzc.__enter__()
+  current_timezone_contexts.append(tzc)
+
   return "Timezone Updated"
+
+
+def resetTimeZone():
+  """Reset the timezone that might have been set by `setTimezone`
+  """
+  current_timezone_contexts.pop().__exit__(None, None, None)

product/ERP5Type/tests/ERP5TypeTestCase.py

@@ -66,6 +66,7 @@ from Products.ERP5Type.Utils import convertToUpperCase, str2bytes
 from Products.ERP5Type.tests.backportUnittest import SetupSiteError
 from Products.ERP5Type.tests.utils import addUserToDeveloperRole
 from Products.ERP5Type.tests.utils import parseListeningAddress
+from Products.ERP5Type.tests.utils import timeZoneContext
 
 # Quiet messages when installing business templates
 install_bt5_quiet = 0
@@ -376,15 +377,10 @@ class ERP5TypeTestCaseMixin(ProcessingNodeTestCase, PortalTestCase):
       self.pinDateTime(None)
 
     def setTimeZoneToUTC(self):
-      # Make sure tests runs with UTC timezone. Some tests are checking values
-      # based on now, and this could give unexpected results:
-      # DateTime("2016/10/31") - DateTime("2016/10/30") = 1.0416666666666667 if
-      # you are running on a timezone like Europe/Paris, while it return 1.0 for
-      # UTC
-      os.environ['TZ'] = "UTC"
-      time.tzset()
-      DateTime._isDST = False
-      DateTime._localzone = DateTime._localzone0 = DateTime._localzone1 = "UTC"
+      # Deprecated, prefer using `timeZoneContext` context manager instead.
+      timezone = timeZoneContext('UTC')
+      timezone.__enter__()
+      self.addCleanup(timezone.__exit__, None, None, None)
 
     def getDefaultSystemPreference(self):
       id = 'default_system_preference'

product/ERP5Type/tests/utils.py

@@ -28,12 +28,16 @@
 
 """Utility functions and classes for unit testing
 """
+import contextlib
+from datetime import datetime
 import errno
 import os
 import logging
+import mock
 import random
 import socket
 import sys
+import time
 import unittest
 import ZODB
 import zLOG
@@ -49,6 +53,7 @@ from email import message_from_string
 from Products.ERP5Type.Globals import PersistentMapping
 from Products.ERP5Type.Utils import simple_decorator
 from Products.ZSQLCatalog.SQLCatalog import Catalog
+import pytz
 import six
 
 class FileUpload(file):
@@ -707,3 +712,35 @@ class SubcontentReindexingWrapper(object):
       self.assertEqual(expected_path_set, catalogged_object_path_set)
     finally:
       Catalog.catalogObjectList = orig_catalogObjectList
+
+
+@contextlib.contextmanager
+def timeZoneContext(timezone):
+  """Context manager to change timezone in tests.
+  """
+  saved_TZ = os.environ.get('TZ')
+  os.environ['TZ'] = timezone
+  time.tzset()
+  if timezone in pytz.all_timezones:
+    _multipleZones = time.daylight
+    _localzone0 = time.tzname[0]
+    _localzone1 = time.tzname[1] if time.daylight else time.tzname[0]
+  else:
+    _multipleZones = False
+    _localzone0 = _localzone1 = timezone
+  if hasattr(sys.modules['DateTime.DateTime'].DateTime, '_localzone0'):
+    patch_target = sys.modules['DateTime.DateTime'].DateTime
+  else:
+    # BBB DateTime 2
+    patch_target = sys.modules['DateTime.DateTime']
+
+  try:
+    with mock.patch.object(patch_target, '_localzone0', new=_localzone0), \
+        mock.patch.object(patch_target, '_localzone1', new=_localzone1), \
+        mock.patch.object(patch_target, '_multipleZones', new=_multipleZones):
+      yield
+  finally:
+    os.environ.pop('TZ')
+    if saved_TZ:
+      os.environ['TZ'] = saved_TZ
+    time.tzset()