Fix formatting of empty-string default values

Author: AA-Turner

docs/changelog.rst

@@ -2,6 +2,9 @@
 Change log
 **********
 
+* Fix formatting of empty-string default values.
+  Patch by Adam Turner.
+
 0.5.1
 #####
 

sphinxarg/ext.py

@@ -87,7 +87,7 @@ def render_list(l, markdown_help, settings=None):
         return all_children
 
 
-def _is_suppressed(item):
+def _is_suppressed(item: str | None) -> bool:
     """Return whether item should not be printed."""
     if item is None:
         return True

sphinxarg/parser.py

@@ -119,9 +119,10 @@ def parse_parser(parser, data=None, **kwargs):
             # Quote default values for string/None types
             default = action.default
             if (
-                action.default not in ['', None, True, False]
-                and action.type in [None, str]
-                and isinstance(action.default, str)
+                default is not None
+                and not isinstance(default, bool)
+                and action.type in {None, str}
+                and isinstance(default, str)
             ):
                 default = f"'{default}'"
 

test/sample-directive-special.py

@@ -24,5 +24,10 @@ def get_parser():
         default=['*.rst', '_txt_', '**strong**', '*italic*', '``code``'],
         nargs='+',
     )
+    parser.add_argument(
+        '--some-text-empty-default',
+        help='Scalar text input',
+        default='',
+    )
 
     return parser