Aware Datetime Support

[henrycjc]

Feature request I suppose, but also looking for guidance. Consider this snippet below where the first test is failing.

I would have expected freezegun to interpret the timezone stored in the datetime object and apply this as a 'tz_offset'. This is not the case.

If it would be acceptable, I'd happily update the documentation with a pull request that this is not intended behaviour, and users should provide the tz_offset kwarg to achieve this. Alternatively, could this feature be added?

I am using pytest:

import pytz
import datetime as dt

TZ = pytz.timezone("Australia/Brisbane")
DT = dt.datetime(2019, 12, 25)


class TestFreezeGun:
    @freezegun.freeze_time(TZ.localize(dt.datetime(2019, 12, 25)))
    def test_freezegun_no_offset_TEST_FAILS(self):
        assert TZ.localize(dt.datetime.now()) == TZ.localize(dt.datetime(2019, 12, 25)) # fails

    @freezegun.freeze_time(TZ.localize(dt.datetime(2019, 12, 25)), tz_offset=10)  # Australia/Brisbane is +10
    def test_freezegun_with_offset(self):
        assert TZ.localize(dt.datetime.now()) == TZ.localize(dt.datetime(2019, 12, 25))