def test_can_falsify_types_without_default_productions():
strategies = StrategyTable()
strategies.define_specification_for(
Bar, lambda s, d: BarStrategy(
s.strategy(descriptors.integers_in_range(0, 100))))
with pytest.raises(MissingSpecification):
StrategyTable.default().strategy(Bar)
verifier = Verifier(strategy_table=strategies)
assert verifier.falsify(
lambda x: False,
Bar,
)[0] == Bar()
assert verifier.falsify(lambda x: x.size() < 3, Bar)[0] == Bar(Bar(Bar()))
def define_binary_strategy(strategies, descriptor):
return strat.BinaryStringStrategy(
strategy=strategies.strategy([descriptors.integers_in_range(0, 255)]),
descriptor=binary_type,
)
def test_can_produce_and_minimize_long_lists_of_only_one_element():
def is_a_monoculture(xs):
assume(len(xs) >= 10)
return len(set(xs)) > 1
falsify(is_a_monoculture, [descriptors.integers_in_range(0, 10)])
assert x == 42
@fails
@given(text_type, text_type)
def test_text_addition_is_not_commutative(x, y):
assert x + y == y + x
@fails
@given(binary_type, binary_type)
def test_binary_addition_is_not_commutative(x, y):
assert x + y == y + x
@given(integers_in_range(1, 10))
def test_integers_are_in_range(x):
assert 1 <= x <= 10
def test_does_not_catch_interrupt_during_falsify():
calls = [0]
@given(int)
def flaky_base_exception(x):
if not calls[0]:
calls[0] = 1
raise KeyboardInterrupt()
with pytest.raises(KeyboardInterrupt):
flaky_base_exception()