tests/fakepatchtime.py

testing: allow Hypothesis to enable extensions

This adds support for testing extensions, including both tests
that extensions don't change behaviour and test for specific
commands.

We use the precondition system to determine what commands are
available to us. If we never use any commands enabled by an
extension then that extension is *skippable* and should not
have changed the behaviour of the test. We thus rerun the test
with an environment variable which is designed to turn off the
extension.

# extension to emulate invoking 'patch.internalpatch()' at the time
# specified by '[fakepatchtime] fakenow'

from __future__ import absolute_import

from mercurial import (
    extensions,
    patch as patchmod,
    util,
)

def internalpatch(orig, ui, repo, patchobj, strip,
                  prefix='', files=None,
                  eolmode='strict', similarity=0):
    if files is None:
        files = set()
    r = orig(ui, repo, patchobj, strip,
             prefix=prefix, files=files,
             eolmode=eolmode, similarity=similarity)

    fakenow = ui.config('fakepatchtime', 'fakenow')
    if fakenow:
        # parsing 'fakenow' in YYYYmmddHHMM format makes comparison between
        # 'fakenow' value and 'touch -t YYYYmmddHHMM' argument easy
        fakenow = util.parsedate(fakenow, ['%Y%m%d%H%M'])[0]
        for f in files:
            repo.wvfs.utime(f, (fakenow, fakenow))

    return r

def extsetup(ui):
    extensions.wrapfunction(patchmod, 'internalpatch', internalpatch)