view tests/hypothesishelpers.py @ 48011:8655a77dce94

parser: force a `ValueError` to bytes before passing to `error.ParseError`

I'm not sure what changed before pytype 09-09-2021 (from 04-15-2021), but this
started getting flagged.  I think there's a pytype bug here, because I don't
see how `.lower()` can be getting called on a `ValueError` after it is forced to
a byte string.  That's suppressed for now to make progress.

This fixes:

    File "/mnt/c/Users/Matt/hg/mercurial/parser.py", line 219, in unescapestr: Function bytestr.__init__ was called with the wrong arguments [wrong-arg-types]
             Expected: (self, ints: Iterable[int])
      Actually passed: (self, ints: ValueError)
      Attributes of protocol Iterable[int] are not implemented on ValueError: __iter__
    File "/mnt/c/Users/Matt/hg/mercurial/parser.py", line 219, in unescapestr: No attribute 'lower' on ValueError [attribute-error]
      In Union[ValueError, mercurial.pycompat.bytestr]

Differential Revision: https://phab.mercurial-scm.org/D11471

# 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()