def validate_types_shallow(self) -> None:
"""
Compares the type annotations on a node's fields with those field's actual
values at runtime. Raises a TypeError is a mismatch is found.
Only validates the current node, not any of it's children. For a recursive
version, see :func:`validate_types_deep`.
If you're using a static type checker (highly recommended), this is useless.
However, if your code doesn't use a static type checker, or if you're unable to
statically type your code for some reason, you can use this method to help
validate your tree.
Some (non-typing) validation is done unconditionally during the construction of
a node. That validation does not overlap with the work that
:func:`validate_types_deep` does.
"""
for f in fields(self):
value = getattr(self, f.name)
if not is_value_of_type(value, f.type):
raise TypeError(
f"Expected an instance of {f.type!r} on "
+ f"{type(self).__name__}'s '{f.name}' field, but instead got "
+ f"an instance of {type(value)!r}"
)
def test_not_implemented(self) -> None:
with self.assertRaises(NotImplementedError):
# pyre-ignore Pyre doesn't like the params to AsyncGenerator
is_value_of_type("something", AsyncGenerator[None, None])
def test_basic_pass(self, value, expected_type) -> None:
self.assertTrue(
is_value_of_type(value, expected_type),
f"value {value!r} was supposed to be of type {expected_type!r}",
)
def test_basic_fail(self, value: object,
expected_type: Type[object]) -> None:
self.assertFalse(is_value_of_type(value, expected_type))
def test_not_implemented(self) -> None:
with self.assertRaises(NotImplementedError):
is_value_of_type("something", AsyncGenerator[None, None])
