as_arg adds frozen_time argument to front of list of arguments

Currently the following code does not work with test classes (Django, etc).

https://github.com/spulec/freezegun/blob/master/freezegun/api.py#L669

That line does the following

result = func(time_factory, *args, **kwargs)

That is incompatible with self being the first param to class methods and it behaves differently than most other decorators, which add their argument to the end, not the beginning. Here is an example that doesn’t work

from django.test import TestCase
from freezegun import freeze_time


class MyTest(TestCase):

  @freeze_time('2016-11-01', as_arg=True)
  def test_something_with_time(self, time_factory):
    # freeze_time overrides self instead of time_factory
    # self is now the time_factory variable
    print(self) # <TimeFactory>
    print(time_factory) # <MyTestCase>

It should do this instead.

result = func(*args, time_factory, **kwargs)

This is a backwards incompatible change, but will allow the decorator to be used with class based tests. Would you be open to accepting a PR that makes this breaking change?

[boxed]

I’ve thought this through a bit more now, and think it’s better with a new as_kwarg option. Then there is no backwards compatibility problem and it’s a bit more elegant too I think. What do you think?

[boxed]

I haven’t made it. I would welcome a PR. Seems like it should be an easy change.