view tests/hypothesishelpers.py @ 37295:45b39c69fae0

wireproto: separate commands tables for version 1 and 2 commands

We can't easily reuse existing command handlers for version 2
commands because the response types will be different. e.g. many
commands return nodes encoded as hex. Our new wire protocol is
binary safe, so we'll wish to encode nodes as binary.

We /could/ teach each command handler to look at the protocol
handler and change behavior based on the version in use. However,
this would make logic a bit unwieldy over time and would make
it harder to design a unified protocol handler interface. I think
it's better to create a clean break between version 1 and version 2
of commands on the server.

What I imagine happening is we will have separate @wireprotocommand
functions for each protocol generation. Those functions will parse the
request, dispatch to a common function to process it, then generate
the response in its own, transport-specific manner.

This commit establishes a separate table for tracking version 1
commands from version 2 commands. The HTTP server pieces have been
updated to use this new table.

Most commands are marked as both version 1 and version 2, so there is
little practical impact to this change.

A side-effect of this change is we now rely on transport registration
in wireprototypes.TRANSPORTS and certain properties of the protocol
interface. So a test had to be updated to conform.

Differential Revision: https://phab.mercurial-scm.org/D2982

# 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()