tests/hypothesishelpers.py

resourceutil: account for the non-resource-like file hierarchy under py2exe

After 9e367157a990, config files for py2exe were expected to be in
C:\Program Files\Mercurial\mercurial\defaultrc because of the implied resource
structure of 'mercurial.defaultrc.*.rc', relative to the executable.
Accomodating this would require changes to the WIX and Inno scripts (and perhaps
the script that generates the WIX script), as well as 3rd party bundlers like
TortoiseHg.  But these files aren't read as resources anyway- they fall back to
the filesystem APIs.  (If we really wanted to carry on the charade, the
installer would have to also sprinkle various empty __init__.py files around.)

Instead, this simply prunes the 'mercurial.' portion of the resource name when
run with py2exe.  (PyOxidizer uses the resources API, not the filesystem
fallback, so it is unaffected.)  Since this hack only affects the py2 Windows
installers and is less risky, I think it's reasonable.  We haven't needed to
load any 3rd party resource up to this point, and would have to make packaging
changes anyway to handle that.

Differential Revision: https://phab.mercurial-scm.org/D8058

# 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()