def validate_call()

in src/fmeval/transforms/util.py [0:0]

• 17 lines of code
• 1 McCabe index (conditional complexity)

def validate_call(call_method: Callable) -> Callable:
    """Decorator for the __call__ method of Transforms used for validating input and output.

    This decorator validates that all keys in a Transform's `input_keys` attribute are
    present in the input record that is passed to `__call__` and that the keys that
    are added to the record by the Transform's internal `__call__` logic are limited
    to the keys specified by the Transform's `output_keys` attribute.

    Note that this decorator should only be used by Transforms that mutate their input record,
    as the output key validation may not make sense in the case where a new record object
    (which may not keep all the same keys as the original record) is returned as the output.

    Additionally, this decorator should be used in conjunction with the
    `register_input_output_keys` method, as the `input_keys` and `output_keys` are initialized
    to None in `Transform.__init__`.

    :param call_method: The `__call__` method of a Transform.
    :returns: A wrapper function that performs pre- and post-validation on top of `__call__`.
    """

    def wrapper(self, record: Dict[str, Any]) -> Dict[str, Any]:
        assert_condition(
            self.input_keys is not None,
            "self.input_keys has not been set. You should set this attribute using "
            "the register_input_output_keys method.",
        )
        assert_condition(
            self.output_keys is not None,
            "self.output_keys has not been set. You should set this attribute using "
            "the register_input_output_keys method.",
        )
        validate_existing_keys(record, self.input_keys)
        call_output = call_method(self, record)
        validate_existing_keys(call_output, self.output_keys)
        return call_output

    return wrapper