view tests/hypothesishelpers.py @ 27246:b288fb2724bf

wireproto: config options to disable bundle1

bundle2 is the new and preferred wire protocol format. For various
reasons, server operators may wish to force clients to use it.

One reason is performance. If a repository is stored in generaldelta,
the server must recompute deltas in order to produce the bundle1
changegroup. This can be extremely expensive. For mozilla-central,
bundle generation typically takes a few minutes. However, generating
a non-gd bundle from a generaldelta encoded mozilla-central requires
over 30 minutes of CPU! If a large repository like mozilla-central
were encoded in generaldelta and non-gd clients connected, they could
easily flood a server by cloning.

This patch gives server operators config knobs to control whether
bundle1 is allowed for push and pull operations. The default is to
support legacy bundle1 clients, making this patch backwards compatible.

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

import os
import sys
import traceback

from hypothesis.settings import set_hypothesis_home_dir
import hypothesis.strategies as st
from hypothesis import given, Settings

# 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:
            given(*args, settings=Settings(max_examples=2000), **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()