Fixed type hint for with_default_category decorator which caused type checkers to mistype (#1381)

Author: kmvanbrunt

CHANGELOG.md

@@ -1,3 +1,8 @@
+## 2.5.6 (TBD)
+* Bug Fixes
+   * Fixed type hint for `with_default_category` decorator which caused type checkers to mistype
+     a decorated subclass of `CommandSet` and a plain `CommandSet`.
+
 ## 2.5.5 (November 13, 2024)
 * Bug Fixes
    * Fixed type hints for passing a class method to `with_argparser` and `as_subcommand_to`.

cmd2/command_definition.py

@@ -10,6 +10,7 @@
     Mapping,
     Optional,
     Type,
+    TypeVar,
 )
 
 from .constants import (
@@ -30,8 +31,10 @@
 #: Further refinements are needed to define the input parameters
 CommandFunc = Callable[..., Optional[bool]]
 
+CommandSetType = TypeVar('CommandSetType', bound=Type['CommandSet'])
 
-def with_default_category(category: str, *, heritable: bool = True) -> Callable[[Type['CommandSet']], Type['CommandSet']]:
+
+def with_default_category(category: str, *, heritable: bool = True) -> Callable[[CommandSetType], CommandSetType]:
     """
     Decorator that applies a category to all ``do_*`` command methods in a class that do not already
     have a category specified.
@@ -42,15 +45,15 @@ def with_default_category(category: str, *, heritable: bool = True) -> Callable[
     override the default category.
 
     If `heritable` is set to False, then only the commands declared locally to this CommandSet will be placed in the
-    specified category. Dynamically created commands, and commands declared in sub-classes will not receive this
+    specified category. Dynamically created commands and commands declared in sub-classes will not receive this
     category.
 
     :param category: category to put all uncategorized commands in
     :param heritable: Flag whether this default category should apply to sub-classes. Defaults to True
     :return: decorator function
     """
 
-    def decorate_class(cls: Type[CommandSet]) -> Type[CommandSet]:
+    def decorate_class(cls: CommandSetType) -> CommandSetType:
         if heritable:
             setattr(cls, CLASS_ATTR_DEFAULT_HELP_CATEGORY, category)
 

docs/conf.py

@@ -184,6 +184,7 @@
 nitpick_ignore = [
     ('py:class', 'ArgparseCommandFunc'),
     ('py:class', 'argparse._SubParsersAction'),
+    ('py:class', 'cmd2.command_definition.CommandSetType'),
     ('py:class', 'cmd2.decorators.CommandParent'),
     ('py:class', 'cmd2.decorators.CommandParentType'),
     ('py:class', 'cmd2.utils._T'),