Merge pull request #81 from ShaneEverittM/positional-args-required

Fix help text around positional arguments.

Author: martinjm97

tap/tap.py

@@ -21,6 +21,7 @@
     get_origin,
     GitInfo,
     is_option_arg,
+    is_positional_arg,
     type_to_str,
     get_literals,
     boolean_type,
@@ -159,7 +160,7 @@ def _add_argument(self, *name_or_flags, **kwargs) -> None:
                 kwargs['help'] += type_to_str(self._annotations[variable]) + ', '
 
             # Required/default
-            if kwargs.get('required', False):
+            if kwargs.get('required', False) or is_positional_arg(*name_or_flags):
                 kwargs['help'] += 'required'
             else:
                 kwargs['help'] += f'default={kwargs.get("default", None)}'

tap/utils.py

@@ -171,6 +171,15 @@ def is_option_arg(*name_or_flags) -> bool:
     return any(name_or_flag.startswith('-') for name_or_flag in name_or_flags)
 
 
+def is_positional_arg(*name_or_flags) -> bool:
+    """Returns whether the argument is a positional arg (as opposed to an optional arg).
+
+    :param name_or_flags: Either a name or a list of option strings, e.g. foo or -f, --foo.
+    :return: True if the argument is a positional arg, False otherwise.
+    """
+    return not is_option_arg(*name_or_flags)
+
+
 def tokenize_source(obj: object) -> Generator:
     """Returns a generator for the tokens of the object's source code."""
     source = inspect.getsource(obj)

tests/test_actions.py

@@ -211,6 +211,17 @@ def configure(self):
         args = ExtendListIntTap().parse_args('--arg 1 2 --arg 3 --arg 4 5'.split())
         self.assertEqual(args.arg, [0, 1, 2, 3, 4, 5])
 
+    def test_positional_default(self):
+        class PositionalDefault(Tap):
+            arg: str
+
+            def configure(self):
+                self.add_argument('arg')
+
+        help_regex = r'.*positional arguments:\n.*arg\s*\(str, required\).*'
+        help_text = PositionalDefault().format_help()
+        self.assertRegexpMatches(help_text, help_regex)
+
 
 if __name__ == '__main__':
     unittest.main()