def test_a_verifier_retrieves_previous_failing_examples_from_the_database():
database = ExampleDatabase()
verifier = Verifier(settings=hs.Settings(database=database))
verifier.falsify(lambda x: x < 11, int)
called = []
def save_calls(t):
called.append(t)
return False
verifier2 = Verifier(settings=hs.Settings(database=database))
verifier2.falsify(save_calls, int)
assert called[0] == 11
assert all(0 <= x <= 11 for x in called)
def test_does_not_falsify_if_all_args_given():
verifier = Verifier()
verifier.falsify = None
@given(int, int, verifier=verifier)
def foo(x, y):
pass
foo(1, 2)
def test_can_falsify_in_derandomize_mode():
settings = Settings(derandomize=True)
v = Verifier(settings=settings)
v.falsify(lambda x: x > 0, int)
def smallest_tree(predicate):
d = NAryTree(int, int, int)
strat = strategy(d)
v = Verifier()
return strat.reify(v.falsify(lambda t: not predicate(t), d)[0])
def smallest_tree(predicate):
d = NAryTree(int, int, int)
strat = strategy(d)
v = Verifier()
return strat.reify(v.falsify(lambda t: not predicate(t), d)[0])
def test_a_verifier_can_still_do_its_thing_if_a_saved_example_fails():
database = ExampleDatabase()
verifier = Verifier(settings=hs.Settings(database=database))
verifier.falsify(lambda x: x < 11, int)
verifier2 = Verifier(settings=hs.Settings(database=database))
verifier2.falsify(lambda x: x < 100, int)
def test_a_verifier_saves_any_failing_examples_in_its_database():
database = ExampleDatabase()
verifier = Verifier(settings=hs.Settings(database=database))
counterexample = verifier.falsify(lambda x: x > 0, int)
saved = list(database.storage_for((int, )).fetch())
assert saved == [counterexample]