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# 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/.
from inspect import signature
import pytest
from hypothesis import Verbosity, assume, given, settings
from hypothesis.errors import InvalidArgument, InvalidState
from hypothesis.reporting import with_reporter
from hypothesis.strategies import booleans, functions, integers
from tests.common.debug import check_can_generate_examples
def func_a():
pass
@given(functions(like=func_a, returns=booleans()))
def test_functions_no_args(f):
assert f.__name__ == "func_a"
assert f is not func_a
assert isinstance(f(), bool)
def func_b(a, b, c):
pass
@given(functions(like=func_b, returns=booleans()))
def test_functions_with_args(f):
assert f.__name__ == "func_b"
assert f is not func_b
with pytest.raises(TypeError):
f()
assert isinstance(f(1, 2, 3), bool)
def func_c(**kwargs):
pass
@given(functions(like=func_c, returns=booleans()))
def test_functions_kw_args(f):
assert f.__name__ == "func_c"
assert f is not func_c
with pytest.raises(TypeError):
f(1, 2, 3)
assert isinstance(f(a=1, b=2, c=3), bool)
@given(functions(like=lambda: None, returns=booleans()))
def test_functions_argless_lambda(f):
assert f.__name__ == "<lambda>"
with pytest.raises(TypeError):
f(1)
assert isinstance(f(), bool)
@given(functions(like=lambda a: None, returns=booleans()))
def test_functions_lambda_with_arg(f):
assert f.__name__ == "<lambda>"
with pytest.raises(TypeError):
f()
assert isinstance(f(1), bool)
@pytest.mark.parametrize(
"like,returns,pure",
[
(None, booleans(), False),
(lambda: None, "not a strategy", True),
(lambda: None, booleans(), None),
],
)
def test_invalid_arguments(like, returns, pure):
with pytest.raises(InvalidArgument):
check_can_generate_examples(functions(like=like, returns=returns, pure=pure))
def func_returns_str() -> str:
return "a string"
@given(functions(like=func_returns_str))
def test_functions_strategy_return_type_inference(f):
result = f()
assume(result != "a string")
assert isinstance(result, str)
def test_functions_valid_within_given_invalid_outside():
cache = None
@given(functions())
def t(f):
nonlocal cache
cache = f
assert f() is None
t()
with pytest.raises(InvalidState):
cache()
def test_can_call_default_like_arg():
# This test is somewhat silly, but coverage complains about the uncovered
# branch for calling it otherwise and alternative workarounds are worse.
like, returns, pure = signature(functions).parameters.values()
assert like.default() is None
assert returns.default is ...
assert pure.default is False
def func(arg, *, kwonly_arg):
pass
@given(functions(like=func))
def test_functions_strategy_with_kwonly_args(f):
with pytest.raises(TypeError):
f(1, 2)
f(1, kwonly_arg=2)
f(kwonly_arg=2, arg=1)
def pure_func(arg1, arg2):
pass
@given(
f=functions(like=pure_func, returns=integers(), pure=True),
arg1=integers(),
arg2=integers(),
)
def test_functions_pure_with_same_args(f, arg1, arg2):
# Same regardless of calling convention, unlike functools.lru_cache()
expected = f(arg1, arg2)
assert f(arg1, arg2) == expected
assert f(arg1, arg2=arg2) == expected
assert f(arg1=arg1, arg2=arg2) == expected
assert f(arg2=arg2, arg1=arg1) == expected
@given(
f=functions(like=pure_func, returns=integers(), pure=True),
arg1=integers(),
arg2=integers(),
)
def test_functions_pure_with_different_args(f, arg1, arg2):
r1 = f(arg1, arg2)
r2 = f(arg2, arg1)
assume(r1 != r2)
# If this is never true, the test will fail with Unsatisfiable
@given(
f1=functions(like=pure_func, returns=integers(), pure=True),
f2=functions(like=pure_func, returns=integers(), pure=True),
)
def test_functions_pure_two_functions_different_args_different_result(f1, f2):
r1 = f1(1, 2)
r2 = f2(3, 4)
assume(r1 != r2)
# If this is never true, the test will fail with Unsatisfiable
@given(
f1=functions(like=pure_func, returns=integers(), pure=True),
f2=functions(like=pure_func, returns=integers(), pure=True),
arg1=integers(),
arg2=integers(),
)
def test_functions_pure_two_functions_same_args_different_result(f1, f2, arg1, arg2):
r1 = f1(arg1, arg2)
r2 = f2(arg1, arg2)
assume(r1 != r2)
# If this is never true, the test will fail with Unsatisfiable
@settings(verbosity=Verbosity.verbose)
@given(functions(pure=False))
def test_functions_note_all_calls_to_impure_functions(f):
ls = []
with with_reporter(ls.append):
f()
f()
assert len(ls) == 2
@settings(verbosity=Verbosity.verbose)
@given(functions(pure=True))
def test_functions_note_only_first_to_pure_functions(f):
ls = []
with with_reporter(ls.append):
f()
f()
assert len(ls) == 1
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