def test_false_only_tuple(self) -> None:
with strict_optional_set(False):
fo = false_only(self.tuple(self.fx.a))
assert_equal(fo, NoneType())
with strict_optional_set(True):
fo = false_only(self.tuple(self.fx.a))
assert_equal(fo, UninhabitedType())
def test_mixed_truth_restricted_type(self) -> None:
# join_types against differently restricted truthiness types drops restrictions.
true_any = true_only(AnyType(TypeOfAny.special_form))
false_o = false_only(self.fx.o)
j = join_types(true_any, false_o)
assert_true(j.can_be_true)
assert_true(j.can_be_false)
def test_mixed_truth_restricted_type_simple(self) -> None:
# join_simple against differently restricted truthiness types drops restrictions.
true_a = true_only(self.fx.a)
false_o = false_only(self.fx.o)
j = join_simple(self.fx.o, true_a, false_o)
assert_true(j.can_be_true)
assert_true(j.can_be_false)
def test_false_only_of_instance(self) -> None:
fo = false_only(self.fx.a)
assert_equal(str(fo), "A")
assert_false(fo.can_be_true)
assert_true(fo.can_be_false)
assert_type(Instance, fo)
# The original class still can be true
assert_true(self.fx.a.can_be_true)
def test_false_only_of_union(self) -> None:
with strict_optional_set(True):
tup_type = self.tuple()
# Union of something that is unknown, something that is always true, something
# that is always false
union_type = UnionType([self.fx.a, self.tuple(AnyType(TypeOfAny.special_form)),
tup_type])
assert_equal(len(union_type.items), 3)
fo = false_only(union_type)
assert isinstance(fo, UnionType)
assert_equal(len(fo.items), 2)
assert not fo.items[0].can_be_true
assert fo.items[0].can_be_false
assert fo.items[1] is tup_type
def test_false_only_of_false_type_is_idempotent(self) -> None:
always_false = NoneType()
fo = false_only(always_false)
assert_true(always_false is fo)
def test_false_only_of_true_type_is_uninhabited(self) -> None:
with strict_optional_set(True):
fo = false_only(self.tuple(AnyType(TypeOfAny.special_form)))
assert_type(UninhabitedType, fo)