view tests/hypothesishelpers.py @ 34144:91f0677dc920 stable

repair: preserve phase also when not using generaldelta (issue5678)

It seems like we used to pick the oldest possible version of the
changegroup to use for bundles created by the repair module (used
e.g. by "hg strip" and for temporary bundles by "hg rebase"). I tried
to preserve that behavior when I created the changegroup.safeversion()
method in 3b2ac2115464 (changegroup: introduce safeversion(),
2016-01-19).

However, we have recently chagned our minds and decided that these
commands are only used locally and downgrades are unlikely. That
decicion allowed us to start adding obsmarker and phase information to
these bundles. However, as the bug report shows, it means we get
different behavior e.g. when generaldelta is not enabled (because when
it was enabled, it forced us to use bundle2). The commit that actually
caused the reported bug was 8e3021fd1a44 (strip: include phases in
bundle (BC), 2017-06-15).

So, since we now depend on having more information in the bundles,
let's make sure we instead pick the newest possible changegroup
version.

Differential Revision: https://phab.mercurial-scm.org/D715

# Helper module to use the Hypothesis tool in tests
#
# Copyright 2015 David R. MacIver
#
# For details see http://hypothesis.readthedocs.org

from __future__ import absolute_import, print_function
import os
import sys
import traceback

try:
    # hypothesis 2.x
    from hypothesis.configuration import set_hypothesis_home_dir
    from hypothesis import settings
except ImportError:
    # hypothesis 1.x
    from hypothesis.settings import set_hypothesis_home_dir
    from hypothesis import Settings as settings
import hypothesis.strategies as st
from hypothesis import given

# hypothesis store data regarding generate example and code
set_hypothesis_home_dir(os.path.join(
    os.getenv('TESTTMP'), ".hypothesis"
))

def check(*args, **kwargs):
    """decorator to make a function a hypothesis test

    Decorated function are run immediately (to be used doctest style)"""
    def accept(f):
        # Workaround for https://github.com/DRMacIver/hypothesis/issues/206
        # Fixed in version 1.13 (released 2015 october 29th)
        f.__module__ = '__anon__'
        try:
            with settings(max_examples=2000):
                given(*args, **kwargs)(f)()
        except Exception:
            traceback.print_exc(file=sys.stdout)
            sys.exit(1)
    return accept


def roundtrips(data, decode, encode):
    """helper to tests function that must do proper encode/decode roundtripping
    """
    @given(data)
    def testroundtrips(value):
        encoded = encode(value)
        decoded = decode(encoded)
        if decoded != value:
            raise ValueError(
                "Round trip failed: %s(%r) -> %s(%r) -> %r" % (
                    encode.__name__, value, decode.__name__, encoded,
                    decoded
                ))
    try:
        testroundtrips()
    except Exception:
        # heredoc swallow traceback, we work around it
        traceback.print_exc(file=sys.stdout)
        raise
    print("Round trip OK")


# strategy for generating bytestring that might be an issue for Mercurial
bytestrings = (
    st.builds(lambda s, e: s.encode(e), st.text(), st.sampled_from([
        'utf-8', 'utf-16',
    ]))) | st.binary()