test_direct_strategies.py

# coding=utf-8
#
# This file is part of Hypothesis, which may be found at
# https://github.com/HypothesisWorks/hypothesis/
#
# Most of this work is copyright (C) 2013-2019 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 __future__ import absolute_import, division, print_function

import collections
import decimal
import fractions
import math
from datetime import date, datetime, time, timedelta

import pytest

import hypothesis.strategies as ds
from hypothesis import given, settings
from hypothesis.errors import InvalidArgument
from hypothesis.internal.reflection import nicerepr
from tests.common.debug import minimal
from tests.common.utils import checks_deprecated_behaviour


def fn_test(*fnkwargs):
    fnkwargs = list(fnkwargs)
    return pytest.mark.parametrize(
        ("fn", "args"),
        fnkwargs,
        ids=[
            "%s(%s)" % (fn.__name__, ", ".join(map(nicerepr, args)))
            for fn, args in fnkwargs
        ],
    )


def fn_ktest(*fnkwargs):
    fnkwargs = list(fnkwargs)
    return pytest.mark.parametrize(
        ("fn", "kwargs"),
        fnkwargs,
        ids=[
            "%s(%s)"
            % (
                fn.__name__,
                ", ".join(sorted("%s=%r" % (k, v) for k, v in kwargs.items())),
            )
            for fn, kwargs in fnkwargs
        ],
    )


@fn_ktest(
    (ds.integers, {"min_value": float("nan")}),
    (ds.integers, {"min_value": 2, "max_value": 1}),
    (ds.integers, {"min_value": float("nan")}),
    (ds.integers, {"max_value": float("nan")}),
    (ds.dates, {"min_value": "fish"}),
    (ds.dates, {"max_value": "fish"}),
    (ds.dates, {"min_value": date(2017, 8, 22), "max_value": date(2017, 8, 21)}),
    (ds.datetimes, {"min_value": "fish"}),
    (ds.datetimes, {"max_value": "fish"}),
    (
        ds.datetimes,
        {"min_value": datetime(2017, 8, 22), "max_value": datetime(2017, 8, 21)},
    ),
    (ds.decimals, {"min_value": float("nan")}),
    (ds.decimals, {"max_value": float("nan")}),
    (ds.decimals, {"min_value": 2, "max_value": 1}),
    (ds.decimals, {"max_value": "-snan"}),
    (ds.decimals, {"max_value": complex(1, 2)}),
    (ds.decimals, {"places": -1}),
    (ds.decimals, {"places": 0.5}),
    (ds.decimals, {"max_value": 0.0, "min_value": 1.0}),
    (ds.decimals, {"min_value": 1.0, "max_value": 0.0}),
    (ds.decimals, {"min_value": 0.0, "max_value": 1.0, "allow_infinity": True}),
    (ds.decimals, {"min_value": "inf"}),
    (ds.decimals, {"max_value": "-inf"}),
    (ds.decimals, {"min_value": "-inf", "allow_infinity": False}),
    (ds.decimals, {"max_value": "inf", "allow_infinity": False}),
    (ds.decimals, {"min_value": complex(1, 2)}),
    (ds.decimals, {"min_value": "0.1", "max_value": "0.9", "places": 0}),
    (
        ds.dictionaries,
        {"keys": ds.booleans(), "values": ds.booleans(), "min_size": 10, "max_size": 1},
    ),
    (ds.floats, {"min_value": float("nan")}),
    (ds.floats, {"max_value": float("nan")}),
    (ds.floats, {"min_value": complex(1, 2)}),
    (ds.floats, {"max_value": complex(1, 2)}),
    (ds.floats, {"exclude_min": None}),
    (ds.floats, {"exclude_max": None}),
    (ds.floats, {"exclude_min": True}),  # because min_value=None
    (ds.floats, {"exclude_max": True}),  # because max_value=None
    (ds.fractions, {"min_value": 2, "max_value": 1}),
    (ds.fractions, {"min_value": float("nan")}),
    (ds.fractions, {"max_value": float("nan")}),
    (ds.fractions, {"max_denominator": 0}),
    (ds.fractions, {"max_denominator": 1.5}),
    (ds.fractions, {"min_value": complex(1, 2)}),
    (ds.lists, {"elements": ds.integers(), "min_size": 10, "max_size": 9}),
    (ds.lists, {"elements": ds.integers(), "min_size": -10, "max_size": -9}),
    (ds.lists, {"elements": ds.integers(), "max_size": -9}),
    (ds.lists, {"elements": ds.integers(), "min_size": -10}),
    (ds.lists, {"elements": ds.integers(), "min_size": float("nan")}),
    (ds.lists, {"elements": ds.nothing(), "max_size": 1}),
    (ds.lists, {"elements": "hi"}),
    (ds.lists, {"elements": ds.integers(), "unique_by": 1}),
    (ds.lists, {"elements": ds.integers(), "unique_by": ()}),
    (ds.lists, {"elements": ds.integers(), "unique_by": (1,)}),
    (ds.lists, {"elements": ds.sampled_from([0, 1]), "min_size": 3, "unique": True}),
    (ds.text, {"min_size": 10, "max_size": 9}),
    (ds.text, {"alphabet": [1]}),
    (ds.text, {"alphabet": ["abc"]}),
    (ds.binary, {"min_size": 10, "max_size": 9}),
    (ds.floats, {"min_value": float("nan")}),
    (ds.floats, {"min_value": "0"}),
    (ds.floats, {"max_value": "0"}),
    (ds.floats, {"max_value": 0.0, "min_value": 1.0}),
    (ds.floats, {"min_value": 0.0, "allow_nan": True}),
    (ds.floats, {"max_value": 0.0, "allow_nan": True}),
    (ds.floats, {"min_value": 0.0, "max_value": 1.0, "allow_infinity": True}),
    (ds.floats, {"min_value": float("inf"), "allow_infinity": False}),
    (ds.floats, {"max_value": float("-inf"), "allow_infinity": False}),
    (ds.complex_numbers, {"min_magnitude": float("nan")}),
    (ds.complex_numbers, {"max_magnitude": float("nan")}),
    (ds.complex_numbers, {"max_magnitude": complex(1, 2)}),
    (ds.complex_numbers, {"min_magnitude": -1}),
    (ds.complex_numbers, {"max_magnitude": -1}),
    (ds.complex_numbers, {"min_magnitude": 3, "max_magnitude": 2}),
    (ds.complex_numbers, {"max_magnitude": 2, "allow_infinity": True}),
    (ds.complex_numbers, {"max_magnitude": 2, "allow_nan": True}),
    (ds.fixed_dictionaries, {"mapping": "fish"}),
    (ds.fixed_dictionaries, {"mapping": {1: "fish"}}),
    (ds.dictionaries, {"keys": ds.integers(), "values": 1}),
    (ds.dictionaries, {"keys": 1, "values": ds.integers()}),
    (ds.text, {"alphabet": "", "min_size": 1}),
    (ds.timedeltas, {"min_value": "fish"}),
    (ds.timedeltas, {"max_value": "fish"}),
    (
        ds.timedeltas,
        {"min_value": timedelta(hours=1), "max_value": timedelta(minutes=1)},
    ),
    (ds.times, {"min_value": "fish"}),
    (ds.times, {"max_value": "fish"}),
    (ds.times, {"min_value": time(2, 0), "max_value": time(1, 0)}),
    (ds.uuids, {"version": 6}),
    (ds.characters, {"min_codepoint": -1}),
    (ds.characters, {"min_codepoint": "1"}),
    (ds.characters, {"max_codepoint": -1}),
    (ds.characters, {"max_codepoint": "1"}),
    (ds.characters, {"whitelist_categories": []}),
    (ds.characters, {"whitelist_categories": ["Nd"], "blacklist_categories": ["Nd"]}),
    (ds.slices, {"size": 0}),
    (ds.slices, {"size": None}),
    (ds.slices, {"size": "chips"}),
    (ds.slices, {"size": -1}),
    (ds.slices, {"size": 2.3}),
)
def test_validates_keyword_arguments(fn, kwargs):
    with pytest.raises(InvalidArgument):
        fn(**kwargs).example()


@fn_ktest(
    (ds.integers, {"min_value": 0}),
    (ds.integers, {"min_value": 11}),
    (ds.integers, {"min_value": 11, "max_value": 100}),
    (ds.integers, {"max_value": 0}),
    (ds.integers, {"min_value": -2, "max_value": -1}),
    (ds.decimals, {"min_value": 1.0, "max_value": 1.5}),
    (ds.decimals, {"min_value": "1.0", "max_value": "1.5"}),
    (ds.decimals, {"min_value": decimal.Decimal("1.5")}),
    (ds.decimals, {"max_value": 1.0, "min_value": -1.0, "allow_infinity": False}),
    (ds.decimals, {"min_value": 1.0, "allow_nan": False}),
    (ds.decimals, {"max_value": 1.0, "allow_nan": False}),
    (ds.decimals, {"max_value": 1.0, "min_value": -1.0, "allow_nan": False}),
    (ds.decimals, {"min_value": "-inf"}),
    (ds.decimals, {"max_value": "inf"}),
    (ds.fractions, {"min_value": -1, "max_value": 1, "max_denominator": 1000}),
    (ds.fractions, {"min_value": 1, "max_value": 1}),
    (ds.fractions, {"min_value": 1, "max_value": 1, "max_denominator": 2}),
    (ds.fractions, {"min_value": 1.0}),
    (ds.fractions, {"min_value": decimal.Decimal("1.0")}),
    (ds.fractions, {"min_value": fractions.Fraction(1, 2)}),
    (ds.fractions, {"min_value": "1/2", "max_denominator": 2}),
    (ds.fractions, {"max_value": "1/2", "max_denominator": 3}),
    (ds.lists, {"elements": ds.nothing(), "max_size": 0}),
    (ds.lists, {"elements": ds.integers()}),
    (ds.lists, {"elements": ds.integers(), "max_size": 5}),
    (ds.lists, {"elements": ds.booleans(), "min_size": 5}),
    (ds.lists, {"elements": ds.booleans(), "min_size": 5, "max_size": 10}),
    (ds.sets, {"min_size": 10, "max_size": 10, "elements": ds.integers()}),
    (ds.booleans, {}),
    (ds.just, {"value": "hi"}),
    (ds.integers, {"min_value": 12, "max_value": 12}),
    (ds.floats, {}),
    (ds.floats, {"min_value": 1.0}),
    (ds.floats, {"max_value": 1.0}),
    (ds.floats, {"min_value": float("inf")}),
    (ds.floats, {"max_value": float("-inf")}),
    (ds.floats, {"max_value": 1.0, "min_value": -1.0}),
    (ds.floats, {"max_value": 1.0, "min_value": -1.0, "allow_infinity": False}),
    (ds.floats, {"min_value": 1.0, "allow_nan": False}),
    (ds.floats, {"max_value": 1.0, "allow_nan": False}),
    (ds.floats, {"max_value": 1.0, "min_value": -1.0, "allow_nan": False}),
    (ds.complex_numbers, {}),
    (ds.complex_numbers, {"min_magnitude": 3, "max_magnitude": 3}),
    (ds.complex_numbers, {"max_magnitude": 0}),
    (ds.complex_numbers, {"allow_nan": True}),
    (ds.complex_numbers, {"allow_nan": True, "allow_infinity": True}),
    (ds.complex_numbers, {"allow_nan": True, "allow_infinity": False}),
    (ds.complex_numbers, {"allow_nan": False}),
    (ds.complex_numbers, {"allow_nan": False, "allow_infinity": True}),
    (ds.complex_numbers, {"allow_nan": False, "allow_infinity": False}),
    (ds.complex_numbers, {"max_magnitude": float("inf"), "allow_infinity": True}),
    (ds.sampled_from, {"elements": [1]}),
    (ds.sampled_from, {"elements": [1, 2, 3]}),
    (ds.fixed_dictionaries, {"mapping": {1: ds.integers()}}),
    (ds.dictionaries, {"keys": ds.booleans(), "values": ds.integers()}),
    (ds.text, {"alphabet": "abc"}),
    (ds.text, {"alphabet": ""}),
    (ds.text, {"alphabet": ds.sampled_from("abc")}),
    (ds.characters, {"whitelist_categories": ["N"]}),
    (ds.characters, {"blacklist_categories": []}),
)
def test_produces_valid_examples_from_keyword(fn, kwargs):
    fn(**kwargs).example()


@fn_test((ds.one_of, (1,)), (ds.tuples, (1,)))
def test_validates_args(fn, args):
    with pytest.raises(InvalidArgument):
        fn(*args).example()


@fn_test(
    (ds.one_of, (ds.booleans(), ds.tuples(ds.booleans()))),
    (ds.one_of, (ds.booleans(),)),
    (ds.text, ()),
    (ds.binary, ()),
    (ds.builds, (lambda x, y: x + y, ds.integers(), ds.integers())),
)
def test_produces_valid_examples_from_args(fn, args):
    fn(*args).example()


def test_build_class_with_target_kwarg():
    NamedTupleWithTargetField = collections.namedtuple("Something", ["target"])
    ds.builds(NamedTupleWithTargetField, target=ds.integers()).example()


def test_builds_raises_with_no_target():
    with pytest.raises(InvalidArgument):
        ds.builds().example()


@pytest.mark.parametrize("non_callable", [1, "abc", ds.integers()])
def test_builds_raises_if_non_callable_as_target_kwarg(non_callable):
    with pytest.raises(InvalidArgument):
        ds.builds(target=non_callable).example()


@pytest.mark.parametrize("non_callable", [1, "abc", ds.integers()])
def test_builds_raises_if_non_callable_as_first_arg(non_callable):
    # If there are any positional arguments, then the target (which must be
    # callable) must be specified as the first one.
    with pytest.raises(InvalidArgument):
        ds.builds(non_callable, target=lambda x: x).example()


def test_text_raises_error_on_non_sequence_alphabet():
    with pytest.raises(InvalidArgument):
        ds.text(set("abc")).validate()


def test_tuples_raise_error_on_bad_kwargs():
    with pytest.raises(TypeError):
        ds.tuples(stuff="things")


@given(ds.lists(ds.booleans(), min_size=10, max_size=10))
def test_has_specified_length(xs):
    assert len(xs) == 10


@given(ds.integers(max_value=100))
@settings(max_examples=100)
def test_has_upper_bound(x):
    assert x <= 100


@given(ds.integers(min_value=100))
def test_has_lower_bound(x):
    assert x >= 100


@given(ds.integers(min_value=1, max_value=2))
def test_is_in_bounds(x):
    assert 1 <= x <= 2


@given(ds.fractions(min_value=-1, max_value=1, max_denominator=1000))
def test_fraction_is_in_bounds(x):
    assert -1 <= x <= 1 and abs(x.denominator) <= 1000


@given(ds.fractions(min_value=fractions.Fraction(1, 2)))
def test_fraction_gt_positive(x):
    assert fractions.Fraction(1, 2) <= x


@given(ds.fractions(max_value=fractions.Fraction(-1, 2)))
def test_fraction_lt_negative(x):
    assert x <= fractions.Fraction(-1, 2)


@given(ds.decimals(min_value=-1.5, max_value=1.5, allow_nan=False))
def test_decimal_is_in_bounds(x):
    # decimal.Decimal("-1.5") == -1.5 (not explicitly testable in py2.6)
    assert decimal.Decimal("-1.5") <= x <= decimal.Decimal("1.5")


def test_float_can_find_max_value_inf():
    assert minimal(ds.floats(max_value=float("inf")), lambda x: math.isinf(x)) == float(
        "inf"
    )
    assert minimal(ds.floats(min_value=0.0), lambda x: math.isinf(x)) == float("inf")


def test_float_can_find_min_value_inf():
    minimal(ds.floats(), lambda x: x < 0 and math.isinf(x))
    minimal(ds.floats(min_value=float("-inf"), max_value=0.0), lambda x: math.isinf(x))


def test_can_find_none_list():
    assert minimal(ds.lists(ds.none()), lambda x: len(x) >= 3) == [None] * 3


def test_fractions():
    assert minimal(ds.fractions(), lambda f: f >= 1) == 1


def test_decimals():
    assert minimal(ds.decimals(), lambda f: f.is_finite() and f >= 1) == 1


def test_non_float_decimal():
    minimal(ds.decimals(), lambda d: d.is_finite() and decimal.Decimal(float(d)) != d)


def test_produces_dictionaries_of_at_least_minimum_size():
    t = minimal(
        ds.dictionaries(ds.booleans(), ds.integers(), min_size=2), lambda x: True
    )
    assert t == {False: 0, True: 0}


@given(ds.dictionaries(ds.integers(), ds.integers(), max_size=5))
@settings(max_examples=50)
def test_dictionaries_respect_size(d):
    assert len(d) <= 5


@given(ds.dictionaries(ds.integers(), ds.integers(), max_size=0))
@settings(max_examples=50)
def test_dictionaries_respect_zero_size(d):
    assert len(d) <= 5


@given(ds.lists(ds.none(), max_size=5))
def test_none_lists_respect_max_size(ls):
    assert len(ls) <= 5


@given(ds.lists(ds.none(), max_size=5, min_size=1))
def test_none_lists_respect_max_and_min_size(ls):
    assert 1 <= len(ls) <= 5


@given(ds.iterables(ds.integers(), max_size=5, min_size=1))
def test_iterables_are_exhaustible(it):
    for _ in it:
        pass
    with pytest.raises(StopIteration):
        next(it)


def test_minimal_iterable():
    assert list(minimal(ds.iterables(ds.integers()), lambda x: True)) == []


@checks_deprecated_behaviour
@pytest.mark.parametrize(
    "fn,kwargs",
    [
        (ds.integers, {"min_value": decimal.Decimal("1.5")}),
        (ds.integers, {"max_value": decimal.Decimal("1.5")}),
        (ds.integers, {"min_value": -1.5, "max_value": -0.5}),
        (ds.floats, {"min_value": 1.8, "width": 32}),
        (ds.floats, {"max_value": 1.8, "width": 32}),
        (ds.fractions, {"min_value": "1/3", "max_value": "1/2", "max_denominator": 2}),
        (ds.fractions, {"min_value": "0", "max_value": "1/3", "max_denominator": 2}),
    ],
)
def test_disallowed_bounds_are_deprecated(fn, kwargs):
    fn(**kwargs).example()


@checks_deprecated_behaviour
@pytest.mark.parametrize(
    "fn,kwargs", [(ds.integers, {"min_value": 0.1, "max_value": 0.2})]
)
def test_no_integers_in_bounds(fn, kwargs):
    with pytest.raises(InvalidArgument):
        fn(**kwargs).example()


@checks_deprecated_behaviour
@pytest.mark.parametrize(
    "fn,kwargs",
    [(ds.fractions, {"min_value": "1/3", "max_value": "1/3", "max_denominator": 2})],
)
def test_no_fractions_in_bounds(fn, kwargs):
    with pytest.raises(InvalidArgument):
        fn(**kwargs).example()


@pytest.mark.parametrize("parameter_name", ["min_value", "max_value"])
@pytest.mark.parametrize("value", [-1, 0, 1])
def test_no_infinity_for_min_max_values(value, parameter_name):
    kwargs = {"allow_infinity": False, parameter_name: value}

    @given(ds.floats(**kwargs))
    def test_not_infinite(xs):
        assert not math.isinf(xs)

    test_not_infinite()


@pytest.mark.parametrize("parameter_name", ["min_value", "max_value"])
@pytest.mark.parametrize("value", [-1, 0, 1])
def test_no_nan_for_min_max_values(value, parameter_name):
    kwargs = {"allow_nan": False, parameter_name: value}

    @given(ds.floats(**kwargs))
    def test_not_nan(xs):
        assert not math.isnan(xs)

    test_not_nan()