def test_use_subclasses_of_arguments(self):
# Even though the argument below is typed as the base class, the fact
# that a faulty implementation exists is enough to produce a
# counterexample:
def f(foo: Cat) -> int:
""" post: _ == 1 """
return foo.size()
# Type repo doesn't load crosshair classes by default; load manually:
type_repo._add_class(Cat)
type_repo._add_class(BiggerCat)
self.assertEqual(*check_fail(f))
def test_range_fail(self) -> None:
def f(l: List[int]) -> List[int]:
'''
pre: len(l) == 3
post: len(_) > len(l)
'''
n: List[int] = []
for i in range(len(l)):
n.append(l[i] + 1)
return n
self.assertEqual(*check_fail(f))
def test_dicts_inside_lists(self) -> None:
def f(dicts: List[Dict[int, int]]) -> Dict[int, int]:
'''
pre: len(dicts) <= 1 # to narrow search space (would love to make this larger)
post: len(_) <= len(dicts)
'''
ret = {}
for d in dicts:
ret.update(d)
return ret
self.assertEqual(*check_fail(f))
def test_nonlinear(self) -> None:
def make_bigger(x: int, e: int) -> float:
"""
pre: e > 1
post: __return__ != 592704
"""
# Expenentation is not SMT-solvable. (z3 gives unsat for this)
# But CrossHair gracefully falls back to realized values, yielding
# the counterexample of: 84 ** 3
return x**e
self.assertEqual(*check_fail(make_bigger))
def TODO_test_dict_deep_equality(self) -> None: # This is too challenging right now.
# TODO: 'set' type has no __args__
def f(a: Dict[bool, Set], b: Dict[str, List[Set[float]]]) -> object:
'''
pre: a == {True: set()}
pre: b == {'': [set(), {1.0}]}
post: _
'''
if a == {True: set()}:
if b == {'': [set(), {1.0}]}:
return False
return True
self.assertEqual(*check_fail(f))
def test_equality(self) -> None:
def f(l: List[int]) -> List[int]:
"""
pre: len(l) > 0
post: _ != l
"""
# extra check for positive equality:
assert l == [x for x in l], "list does not equal itself"
nl = l[:]
nl[0] = 42
return nl
self.assertEqual(*check_fail(f))
def test_symbolic_supports(self) -> None:
def f(
a: SupportsAbs,
f: SupportsFloat,
i: SupportsInt,
r: SupportsRound,
c: SupportsComplex,
b: SupportsBytes,
) -> float:
""" post: _.real <= 0 """
return abs(a) + float(f) + int(i) + round(r) + complex(c) + len(
bytes(b))
self.assertEqual(*check_fail(f))
def TODO_test_dict_deep_equality(
self, ) -> None: # This is too challenging right now.
def f(a: Dict[bool, set], b: Dict[str, List[Set[float]]]) -> object:
"""
pre: a == {True: set()}
pre: b == {'': [set(), {1.0}]}
post: _
"""
if a == {True: set()}:
if b == {"": [set(), {1.0}]}:
return False
return True
self.assertEqual(*check_fail(f))
def test_number_parse(self) -> None:
number_re = re.compile(r"(-?(?:0|[1-9]\d*))(\.\d+)?([eE][-+]?\d+)?")
def f(s: str):
"""
pre: len(s) == 4
post: not _
"""
return bool(number_re.fullmatch(s))
self.assertEqual(*check_fail(
f,
AnalysisOptionSet(max_iterations=20,
per_path_timeout=5,
per_condition_timeout=20),
))
def test_dicts_inside_lists_with_identity(self) -> None:
# NOTE: the message is a little confusing because repr()
# hides the fact that the identity of the lists is the same.
def f(dicts: List[Dict[int, int]]):
'''
Removes duplicate keys.
pre: len(dicts) == 2
pre: len(dicts[0]) == 1
post: len(dicts[0]) == 1
'''
seen: Set[int] = set()
for d in dicts:
for k in d.keys():
if k in seen:
del d[k]
else:
seen.add(k)
self.assertEqual(*check_fail(f))
def test_runtime_type(self) -> None:
def f(t: dict) -> dict:
''' post: t != {1: 2} '''
return t
self.assertEqual(*check_fail(f))
def test_simple_bool_with_fail(self) -> None:
def f(a: bool, b: bool) -> bool:
''' post: _ == a '''
return True if a else b
self.assertEqual(*check_fail(f))
def test_match_basic_fail2(self) -> None:
def f(s: str) -> bool:
""" post: implies(_, len(s) <= 3) """
return bool(re.compile("ab?c").match(s))
self.assertEqual(*check_fail(f))
def test_int_str_comparison_fail(self) -> None:
def f(a: int, b: str) -> Tuple[bool, bool]:
''' post: (not _[0]) or (not _[1]) '''
return (a != b, b != a)
self.assertEqual(*check_fail(f))
def test_runtime_type(self) -> None:
def f(t: Tuple) -> Tuple:
''' post: t != (1, 2) '''
return t
self.assertEqual(*check_fail(f))
def test_symbolic_type_can_be_subclass(self) -> None:
def f(typ: Type[Cat]):
''' post: _ == "<class '__main__.Cat'>" '''
return str(typ)
# False when the type is instantiated as "BiggerCat":
self.assertEqual(*check_fail(f))
def test_str_comparison_fail(self) -> None:
def f(s1: str, s2: str) -> bool:
''' post: _ '''
return s1 >= s2
self.assertEqual(*check_fail(f))
def test_cast_to_bool_fail(self) -> None:
def f(a: str) -> str:
''' post: a '''
return a
self.assertEqual(*check_fail(f))
def test_prefixing_fail(self) -> None:
def f(a: str, indent: bool) -> str:
''' post: len(_) == len(a) + indent '''
return (' ' if indent else '') + a
self.assertEqual(*check_fail(f))
def test_specific_length(self) -> None:
def f(b: bytes) -> int:
""" post: _ != 5 """
return len(b)
self.assertEqual(*check_fail(f))
def test_int_div_fail(self) -> None:
def f(a: int, b: int) -> int:
''' post: a <= _ <= b '''
return (a + b) // 2
self.assertEqual(*check_fail(f))
def test_subtype_union(self) -> None:
def f(s: Set[Union[int, str]]) -> None:
''' post: not (42 in s and '42' in s) '''
return s
self.assertEqual(*check_fail(f))
def test_type_comparison(self) -> None:
def f(t: Type) -> bool:
''' post: _ '''
return t == int
self.assertEqual(*check_fail(f))
def test_symbolic_types_fail(self) -> None:
def f(typ: Type):
''' post: _ '''
return issubclass(typ, str)
self.assertEqual(*check_fail(f))
def test_bool_ors_fail(self) -> None:
def f(a: bool, b: bool, c: bool, d: bool) -> bool:
''' post: _ == (a ^ b) or (c ^ d) '''
return a or b or c or d
self.assertEqual(*check_fail(f))
def test_negative_index_slicing(self) -> None:
def f(s: str) -> Tuple[str, str]:
''' post: sum(map(len, _)) == len(s) - 1 '''
idx = s.find(':')
return (s[:idx], s[idx + 1:])
self.assertEqual(*check_fail(f)) # (fails when idx == -1)
def test_generic_object_equality(self) -> None:
def f(thing: object, i: int):
''' post: not _ '''
return thing == i
self.assertEqual(*check_fail(f))
def test_enum_in_container(self) -> None:
def f(colors: List[Color]) -> bool:
''' post: not _ '''
return Color.RED in colors and Color.BLUE in colors
self.assertEqual(*check_fail(f))
def test_hashable_values_fail(self) -> None:
def f(b: bool, i: int, t: Tuple[str, ...], s: FrozenSet[float]) -> int:
''' post: _ % 10 != 0 '''
return hash((i, t, s))
self.assertEqual(*check_fail(f))
def test_symbolic_two_arg_callable(self) -> None:
def f(i: int, callable: Callable[[int, int], int]) -> int:
''' post: _ != i '''
return callable(i, i)
self.assertEqual(*check_fail(f))
