File: test_sampled_from.py

package info (click to toggle)
python-hypothesis 6.67.1-1
  • links: PTS, VCS
  • area: main
  • in suites: bookworm
  • size: 14,220 kB
  • sloc: python: 46,711; ruby: 1,107; sh: 255; xml: 140; makefile: 49; javascript: 12
file content (192 lines) | stat: -rw-r--r-- 5,519 bytes parent folder | download
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
# This file is part of Hypothesis, which may be found at
# https://github.com/HypothesisWorks/hypothesis/
#
# Copyright the Hypothesis Authors.
# Individual contributors are listed in AUTHORS.rst and the git log.
#
# 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/.

import collections
import enum

import pytest

from hypothesis import given, strategies as st
from hypothesis.errors import (
    FailedHealthCheck,
    InvalidArgument,
    StopTest,
    Unsatisfiable,
)
from hypothesis.internal.conjecture.data import ConjectureData
from hypothesis.strategies import sampled_from
from hypothesis.strategies._internal.misc import JustStrategy
from hypothesis.strategies._internal.strategies import (
    FilteredStrategy,
    filter_not_satisfied,
)

from tests.common.utils import fails_with

an_enum = enum.Enum("A", "a b c")

an_ordereddict = collections.OrderedDict([("a", 1), ("b", 2), ("c", 3)])


@fails_with(InvalidArgument)
def test_cannot_sample_sets():
    sampled_from(set("abc")).example()


def test_can_sample_sequence_without_warning():
    sampled_from([1, 2, 3]).example()


def test_can_sample_ordereddict_without_warning():
    sampled_from(an_ordereddict).example()


@given(sampled_from(an_enum))
def test_can_sample_enums(member):
    assert isinstance(member, an_enum)


@fails_with(FailedHealthCheck)
@given(sampled_from(range(10)).filter(lambda x: x < 0))
def test_unsat_filtered_sampling(x):
    raise AssertionError


@fails_with(Unsatisfiable)
@given(sampled_from(range(2)).filter(lambda x: x < 0))
def test_unsat_filtered_sampling_in_rejection_stage(x):
    # Rejecting all possible indices before we calculate the allowed indices
    # takes an early exit path, so we need this test to cover that branch.
    raise AssertionError


def test_easy_filtered_sampling():
    x = sampled_from(range(100)).filter(lambda x: x == 0).example()
    assert x == 0


@given(sampled_from(range(100)).filter(lambda x: x == 99))
def test_filtered_sampling_finds_rare_value(x):
    assert x == 99


@given(st.sets(st.sampled_from(range(50)), min_size=50))
def test_efficient_sets_of_samples(x):
    assert x == set(range(50))


@given(st.dictionaries(keys=st.sampled_from(range(50)), values=st.none(), min_size=50))
def test_efficient_dicts_with_sampled_keys(x):
    assert set(x) == set(range(50))


@given(
    st.lists(
        st.tuples(st.sampled_from(range(20)), st.builds(list)),
        min_size=20,
        unique_by=lambda asdf: asdf[0],
    )
)
def test_efficient_lists_of_tuples_first_element_sampled_from(x):
    assert {first for first, *_ in x} == set(range(20))


@given(st.lists(st.sampled_from([0] * 100), unique=True))
def test_does_not_include_duplicates_even_when_duplicated_in_collection(ls):
    assert len(ls) <= 1


@given(
    st.sets(
        st.sampled_from(range(50))
        .map(lambda x: x * 2)
        .filter(lambda x: x % 3)
        .map(lambda x: x // 2),
        min_size=33,
    )
)
def test_efficient_sets_of_samples_with_chained_transformations(x):
    assert x == {x for x in range(50) if (x * 2) % 3}


@st.composite
def stupid_sampled_sets(draw):
    result = set()
    s = st.sampled_from(range(20)).filter(lambda x: x % 3).map(lambda x: x * 2)
    while len(result) < 13:
        result.add(draw(s.filter(lambda x: x not in result)))
    return result


@given(stupid_sampled_sets())
def test_efficient_sets_of_samples_with_chained_transformations_slow_path(x):
    # This deliberately exercises the standard filtering logic without going
    # through the special-case handling of UniqueSampledListStrategy.
    assert x == {x * 2 for x in range(20) if x % 3}


@fails_with(Unsatisfiable)
@given(FilteredStrategy(st.sampled_from([None, False, ""]), conditions=(bool,)))
def test_unsatisfiable_explicit_filteredstrategy_sampled(x):
    raise AssertionError("Unreachable because there are no valid examples")


@fails_with(Unsatisfiable)
@given(FilteredStrategy(st.none(), conditions=(bool,)))
def test_unsatisfiable_explicit_filteredstrategy_just(x):
    raise AssertionError("Unreachable because there are no valid examples")


def test_transformed_just_strategy():
    data = ConjectureData.for_buffer(bytes(100))
    s = JustStrategy([1]).map(lambda x: x * 2)
    assert s.do_draw(data) == 2
    sf = s.filter(lambda x: False)
    assert isinstance(sf, JustStrategy)
    assert sf.do_filtered_draw(data) == filter_not_satisfied
    with pytest.raises(StopTest):
        sf.do_draw(data)


@given(st.lists(st.sampled_from(range(100)), max_size=3, unique=True))
def test_max_size_is_respected_with_unique_sampled_from(ls):
    assert len(ls) <= 3


@given(st.lists(st.sampled_from([0, 0.0]), unique=True, min_size=1))
def test_issue_2247_regression(ls):
    assert len(ls) == 1


@given(st.data())
def test_mutability_1(data):
    # See https://github.com/HypothesisWorks/hypothesis/issues/2507
    x = [1]
    s = st.sampled_from(x)
    x.append(2)
    assert data.draw(s) != 2


@given(st.data())
def test_mutability_2(data):
    x = [1]
    s = st.sampled_from(x)
    assert data.draw(s) != 2
    x.append(2)
    assert data.draw(s) != 2


class AnnotationsInsteadOfElements(enum.Enum):
    a: "a"


def test_suggests_elements_instead_of_annotations():
    with pytest.raises(InvalidArgument, match="Cannot sample.*annotations.*dataclass"):
        st.sampled_from(AnnotationsInsteadOfElements).example()