lib.Cmd.AbstractCmd.aliases: Add property

Add a property aliases to AbstractCmd in prepeparation for commands to bear multiple names / abbreviations / aliases.
The App.add_cmds_to_parser() function uses parse_known_args() to determine which subcommand was invoked, then conditionally registers nested subcommands. The lookup dictionary (scs) contains only canonical names, not aliases, so add them too, otherwise using the alias instead of the canonical name causes the lookup to fail and nested subcommands to never be registered.
Fix: Register each alias in scs pointing to the same SubCommand object, and deduplicate with id(sc) when iterating in all=True mode to avoid infinite recursion on help output.
Signed-off-by: Jan Lindemann <jan@janware.com>

src/python/jw/pkg/cmds/Cmd.py

@@ -6,12 +6,19 @@ from ..App import App as Parent
 from ..CmdBase import CmdBase as Base
 
 if TYPE_CHECKING:
+    from typing import Iterable
     from ..lib.Distro import Distro
 
 class Cmd(Base):  # export
 
-    def __init__(self, parent: Parent, name: str, help: str) -> None:
-        super().__init__(parent, name, help)
+    def __init__(
+        self,
+        parent: Parent,
+        name: str,
+        help: str,
+        aliases: Iterable[str] | None = None
+    ) -> None:
+        super().__init__(parent, name, help, aliases = aliases)
 
     async def _run(self, args):
         # Missing subcommand

src/python/jw/pkg/lib/App.py

@@ -56,6 +56,7 @@ class App:  # export
                 cmd.name,
                 help = cmd.help,
                 description = cmd.description,
+                aliases = cmd.aliases,
                 formatter_class = ArgumentDefaultsHelpFormatter,
             )
             parser.set_defaults(func = cmd.run)
@@ -88,14 +89,24 @@ class App:  # export
             for cmd in cmds:
                 cmd.set_parent(parent)
                 scs[cmd.name] = SubCommand(cmd, add_cmd_to_parser(cmd, subparsers))
+                for alias in cmd.aliases:
+                    scs[alias] = scs[cmd.name]
             if all:
+                seen: set[int] = set()
                 for sc in scs.values():
-                    add_cmds_to_parser(sc.cmd, sc.parser, sc.cmd.children, all = all)
+                    if id(sc) not in seen:
+                        seen.add(id(sc))
+                        add_cmds_to_parser(
+                            sc.cmd, sc.parser, sc.cmd.children, all = all
+                        )
                 return
             args, unknown = self.__parser.parse_known_args()
-            if args.command in scs:
-                sc = scs[args.command]
-                add_cmds_to_parser(sc.cmd, sc.parser, sc.cmd.children, all = all)
+            cmd_name = getattr(args, 'command', None)
+            if cmd_name in scs:
+                sc = scs[cmd_name]
+                add_cmds_to_parser(
+                    sc.cmd, sc.parser, sc.cmd.children, all = all
+                )
 
         from .Cmd import AbstractCmd
 

src/python/jw/pkg/lib/Cmd.py

@@ -10,7 +10,7 @@ from .Types import LoadTypes, Types
 
 if TYPE_CHECKING:
     from argparse import ArgumentParser
-    from typing import Any
+    from typing import Any, Iterable
 
     from .App import App
 
@@ -150,6 +150,13 @@ class AbstractCmd(abc.ABC):
     def description(self) -> str:
         return self._description()
 
+    def _aliases(self) -> Iterable[str]:
+        return []
+
+    @property
+    def aliases(self) -> Iterable[str]:
+        return self._aliases()
+
 class Cmd(AbstractCmd):  # export
 
     def __init__(
@@ -157,12 +164,14 @@ class Cmd(AbstractCmd):  # export
         parent: App | Cmd,
         name: str,
         help: str,
-        description: str | None = None
+        description: str | None = None,
+        aliases: Iterable[str] | None = None
     ) -> None:
         super().__init__(parent)
         self.__name = name
         self.__help = help
         self.__description = description if description else help
+        self.__aliases = aliases if aliases else []
 
     def _name(self) -> str:
         return self.__name
@@ -172,3 +181,6 @@ class Cmd(AbstractCmd):  # export
 
     def _description(self) -> str:
         return self.__description
+
+    def _aliases(self) -> Iterable[str]:
+        return self.__aliases