test_poisoned_lists.py

# This file is part of Hypothesis, which may be found at
# https://github.com/HypothesisWorks/hypothesis/
#
# Most of this work is copyright (C) 2013-2020 David R. MacIver
# (david@drmaciver.com), but it contains contributions by others. See
# CONTRIBUTING.rst for a full list of people who may hold copyright, and
# consult the git log if you need to determine who owns an individual
# contribution.
#
# This Source Code Form is subject to the terms of the Mozilla Public License,
# v. 2.0. If a copy of the MPL was not distributed with this file, You can
# obtain one at https://mozilla.org/MPL/2.0/.
#
# END HEADER

from random import Random

import pytest

from hypothesis import settings, strategies as st
from hypothesis.internal.compat import ceil
from hypothesis.internal.conjecture import utils as cu
from hypothesis.internal.conjecture.engine import ConjectureData, ConjectureRunner
from hypothesis.strategies._internal import SearchStrategy

POISON = "POISON"


class Poisoned(SearchStrategy):
    def __init__(self, poison_chance):
        SearchStrategy.__init__(self)
        self.__poison_chance = poison_chance
        self.__ints = st.integers(0, 10)

    def do_draw(self, data):
        if cu.biased_coin(data, self.__poison_chance):
            return POISON
        else:
            return data.draw(self.__ints)


class LinearLists(SearchStrategy):
    def __init__(self, elements, size):
        SearchStrategy.__init__(self)
        self.__length = st.integers(0, size)
        self.__elements = elements

    def do_draw(self, data):
        return [data.draw(self.__elements) for _ in range(data.draw(self.__length))]


class Matrices(SearchStrategy):
    def __init__(self, elements, size):
        SearchStrategy.__init__(self)
        self.__length = st.integers(0, ceil(size ** 0.5))
        self.__elements = elements

    def do_draw(self, data):
        n = data.draw(self.__length)
        m = data.draw(self.__length)

        return [data.draw(self.__elements) for _ in range(n * m)]


LOTS = 10 ** 6

TRIAL_SETTINGS = settings(max_examples=LOTS, database=None)


@pytest.mark.parametrize(
    "seed", [2282791295271755424, 1284235381287210546, 14202812238092722246, 26097]
)
@pytest.mark.parametrize("size", [5, 10, 20])
@pytest.mark.parametrize("p", [0.01, 0.1])
@pytest.mark.parametrize("strategy_class", [LinearLists, Matrices])
def test_minimal_poisoned_containers(seed, size, p, strategy_class, monkeypatch):
    elements = Poisoned(p)
    strategy = strategy_class(elements, size)

    def test_function(data):
        v = data.draw(strategy)
        data.output = repr(v)
        if POISON in v:
            data.mark_interesting()

    runner = ConjectureRunner(
        test_function, random=Random(seed), settings=TRIAL_SETTINGS
    )
    runner.run()
    (v,) = runner.interesting_examples.values()
    result = ConjectureData.for_buffer(v.buffer).draw(strategy)
    assert len(result) == 1