tests/mockmakedate.py

rust-re2: add wrapper for calling Re2 from Rust

This assumes that Re2 is installed following Google's guide. I am not sure
how we want to integrate it in the project, but I think a follow-up patch would
be more appropriate for such work.
As it stands, *not* having Re2 installed results in a compilation error, which
is a problem as it breaks install compatibility. Hence, this is gated behind
a non-default `with-re2` compilation feature.

Differential Revision: https://phab.mercurial-scm.org/D7910

# mock out util.makedate() to supply testable values

from __future__ import absolute_import

import os

from mercurial import pycompat
from mercurial.utils import dateutil


def mockmakedate():
    filename = os.path.join(os.environ['TESTTMP'], 'testtime')
    try:
        with open(filename, 'rb') as timef:
            time = float(timef.read()) + 1
    except IOError:
        time = 0.0
    with open(filename, 'wb') as timef:
        timef.write(pycompat.bytestr(time))
    return (time, 0)


dateutil.makedate = mockmakedate