~mailman-coders/mailman/3.0

# Copyright (C) 2009-2015 by the Free Software Foundation, Inc.

#

# This file is part of GNU Mailman.

#

# GNU Mailman is free software: you can redistribute it and/or modify it under

# the terms of the GNU General Public License as published by the Free

# Software Foundation, either version 3 of the License, or (at your option)

# any later version.

#

# GNU Mailman is distributed in the hope that it will be useful, but WITHOUT

# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for

# more details.

#

# You should have received a copy of the GNU General Public License along with

# GNU Mailman.  If not, see <http://www.gnu.org/licenses/>.

"""Datetime utilities.

Use these functions to produce variable times rather than the built-in

datetime.datetime.now() and datetime.date.today().  These are better

instrumented for testing purposes.

"""

__all__ = [

    'DateFactory',

    'RFC822_DATE_FMT',

    'UTC',

    'factory',

    'now',

    'today',

    'utc',

    ]

import datetime

from mailman.testing import layers

# Python always sets the locale to 'C' locale unless the user explicitly calls

# locale.setlocale(locale.LC_ALL, '').  Since we never do this in Mailman (and

# no library better do it either!) this will safely give us expected RFC 5322

# Date headers.

RFC822_DATE_FMT = '%a, %d %b %Y %H:%M:%S %z'

# Definition of UTC timezone, taken from

# http://docs.python.org/library/datetime.html

ZERO = datetime.timedelta(0)

class UTC(datetime.tzinfo):

    def utcoffset(self, dt):

        return ZERO

    def tzname(self, dt):

        return 'UTC'

    def dst(self, dt):

        return ZERO

utc = UTC()

_missing = object()

class DateFactory:

    """A factory for today() and now() that works with testing."""

    # The predictable time.

    predictable_now = None

    predictable_today = None

    def now(self, tz=_missing, strip_tzinfo=True):

        # We can't automatically fast-forward because some tests require us to

        # stay on the same day for a while, e.g. autorespond.txt.

        if tz is _missing:

            tz = utc

        # Storm cannot yet handle datetimes with tz suffixes.  Assume we're

        # using UTC datetimes everywhere, so set the tzinfo to None.  This

        # does *not* change the actual time values.  LP: #280708

        tz_now = (self.predictable_now

                  if layers.is_testing()

                  else datetime.datetime.now(tz))

        return (tz_now.replace(tzinfo=None)

                if strip_tzinfo

                else tz_now)

    def today(self):

        return (self.predictable_today

                if layers.is_testing()

                else datetime.date.today())

    @classmethod

    def reset(cls):

        cls.predictable_now = datetime.datetime(2005, 8, 1, 7, 49, 23,

                                                tzinfo=utc)

        cls.predictable_today = cls.predictable_now.date()

    @classmethod

    def fast_forward(cls, days=1):

        cls.predictable_now += datetime.timedelta(days=days)

        cls.predictable_today = cls.predictable_now.date()

factory = DateFactory()

factory.reset()

today = factory.today

now = factory.now

layers.MockAndMonkeyLayer.register_reset(factory.reset)