def test_contract_filter_inline(n):
assert -1 <= fulfill(invert)(n) <= 1
def test_no_vacuous_fulfill(f):
with pytest.raises(InvalidArgument):
fulfill(f)
from hypothesis import given
from hypothesis.errors import InvalidArgument
from hypothesis.strategies import builds, integers
from hypothesis.extra.dpcontracts import fulfill
def identity(x):
return x
@require('division is undefined for zero', lambda args: args.n != 0)
def invert(n):
return 1 / n
@given(builds(fulfill(invert), integers()))
def test_contract_filter_builds(x):
assert -1 <= x <= 1
@given(integers())
def test_contract_filter_inline(n):
assert -1 <= fulfill(invert)(n) <= 1
@pytest.mark.parametrize('f', [int, identity, lambda x: None])
def test_no_vacuous_fulfill(f):
with pytest.raises(InvalidArgument):
fulfill(f)