#!/usr/bin/env python3
+# © Copyright 2021-2022, Scott Gasch
+
+"""Utility functions for dealing with typing."""
+
import logging
from typing import Any, Optional
def unwrap_optional(x: Optional[Any]) -> Any:
+ """Unwrap an Optional[Type] argument returning a Type value back.
+ If the Optional[Type] argument is None, however, raise an exception.
+ Use this to satisfy most type checkers that a value that could
+ be None isn't so as to drop the Optional typing hint.
+
+ >>> x: Optional[bool] = True
+ >>> unwrap_optional(x)
+ True
+
+ >>> y: Optional[str] = None
+ >>> unwrap_optional(y)
+ Traceback (most recent call last):
+ ...
+ AssertionError: Argument to unwrap_optional was unexpectedly None
+
+ """
if x is None:
msg = 'Argument to unwrap_optional was unexpectedly None'
logger.critical(msg)
raise AssertionError(msg)
return x
+
+
+if __name__ == '__main__':
+ import doctest
+
+ doctest.testmod()