refactor: ♻️ Refactor weird checks in CogMeta and fix some typing and other qol things

discord/cog.py

@@ -31,7 +31,17 @@
 import pathlib
 import sys
 import types
-from typing import Any, Callable, ClassVar, Generator, Mapping, TypeVar, overload
+from collections.abc import Generator, Mapping
+from typing import (
+    TYPE_CHECKING,
+    Any,
+    Callable,
+    ClassVar,
+    TypeVar,
+    overload,
+)
+
+from typing_extensions import TypeGuard
 
 import discord.utils
 
@@ -43,6 +53,10 @@
     _BaseCommand,
 )
 
+if TYPE_CHECKING:
+    from .ext.bridge import BridgeCommand
+
+
 __all__ = (
     "CogMeta",
     "Cog",
@@ -59,6 +73,118 @@ def _is_submodule(parent: str, child: str) -> bool:
     return parent == child or child.startswith(f"{parent}.")
 
 
+def _is_bridge_command(command: Any) -> TypeGuard[BridgeCommand]:
+    return getattr(command, "__bridge__", False)
+
+
+def _name_filter(c: Any) -> str:
+    return (
+        "app"
+        if isinstance(c, ApplicationCommand)
+        else ("bridge" if not _is_bridge_command(c) else "ext")
+    )
+
+
+def _validate_name_prefix(base_class: type, name: str) -> None:
+    if name.startswith(("cog_", "bot_")):
+        raise TypeError(
+            f"Commands or listeners must not start with cog_ or bot_ (in method {base_class}.{name})"
+        )
+
+
+def _process_attributes(
+    base: type,
+) -> tuple[dict[str, Any], dict[str, Any]]:  # pyright: ignore[reportExplicitAny]
+    commands: dict[str, _BaseCommand | BridgeCommand] = {}
+    listeners: dict[str, Callable[..., Any]] = {}
+
+    for attr_name, attr_value in base.__dict__.items():
+        if attr_name in commands:
+            del commands[attr_name]
+        if attr_name in listeners:
+            del listeners[attr_name]
+
+        if getattr(attr_value, "parent", None) and isinstance(
+            attr_value, ApplicationCommand
+        ):
+            # Skip application commands if they are a part of a group
+            # Since they are already added when the group is added
+            continue
+
+        is_static_method = isinstance(attr_value, staticmethod)
+        if is_static_method:
+            attr_value = attr_value.__func__
+
+        if inspect.iscoroutinefunction(attr_value) and getattr(
+            attr_value, "__cog_listener__", False
+        ):
+            _validate_name_prefix(base, attr_name)
+            listeners[attr_name] = attr_value
+            continue
+
+        if isinstance(attr_value, _BaseCommand) or _is_bridge_command(attr_value):
+            if is_static_method:
+                raise TypeError(
+                    f"Command in method {base}.{attr_name!r} must not be staticmethod."
+                )
+            _validate_name_prefix(base, attr_name)
+
+        if isinstance(attr_value, _BaseCommand):
+            commands[attr_name] = attr_value
+
+        if _is_bridge_command(attr_value) and not attr_value.parent:
+            commands[f"ext_{attr_name}"] = attr_value.ext_variant
+            commands[f"app_{attr_name}"] = attr_value.slash_variant
+            commands[attr_name] = attr_value
+            for cmd in getattr(attr_value, "subcommands", []):
+                commands[f"ext_{cmd.ext_variant.qualified_name}"] = cmd.ext_variant
+
+    return commands, listeners
+
+
+def _update_command(
+    command: _BaseCommand | BridgeCommand,
+    guild_ids: list[int],
+    lookup_table: dict[str, _BaseCommand | BridgeCommand],
+    new_cls: type[Cog],
+) -> None:
+    if isinstance(command, ApplicationCommand) and not command.guild_ids and guild_ids:
+        command.guild_ids = guild_ids
+
+    if not isinstance(command, SlashCommandGroup) and not _is_bridge_command(command):
+        # ignore bridge commands
+        cmd: BridgeCommand | _BaseCommand | None = getattr(
+            new_cls,
+            command.callback.__name__,
+            None,  # pyright: ignore[reportUnknownMemberType,reportUnknownArgumentType,reportAttributeAccessIssue]
+        )
+        if _is_bridge_command(cmd):
+            setattr(
+                cmd,
+                f"{_name_filter(command).replace('app', 'slash')}_variant",
+                command,
+            )
+        else:
+            setattr(
+                new_cls,
+                command.callback.__name__,
+                command,  # pyright: ignore [reportAttributeAccessIssue, reportUnknownArgumentType, reportUnknownMemberType]
+            )
+
+        parent: (
+            BridgeCommand | _BaseCommand | None
+        ) = (  # pyright: ignore [reportUnknownMemberType, reportUnknownVariableType]
+            command.parent  # pyright: ignore [reportAttributeAccessIssue]
+        )
+        if parent is not None:
+            # Get the latest parent reference
+            parent = lookup_table[f"{_name_filter(command)}_{parent.qualified_name}"]  # type: ignore # pyright: ignore[reportUnknownMemberType]
+
+            # Update the parent's reference to our self
+            parent.remove_command(command.name)  # type: ignore # pyright: ignore[reportAttributeAccessIssue, reportUnknownMemberType]
+            parent.add_command(command)  # type: ignore # pyright: ignore[reportAttributeAccessIssue, reportUnknownMemberType]
+
+
 class CogMeta(type):
     """A metaclass for defining a cog.
 
@@ -127,7 +253,7 @@ async def bar(self, ctx):
 
     __cog_name__: str
     __cog_settings__: dict[str, Any]
-    __cog_commands__: list[ApplicationCommand]
+    __cog_commands__: list[_BaseCommand | BridgeCommand]
     __cog_listeners__: list[tuple[str, str]]
     __cog_guild_ids__: list[int]
 
@@ -142,128 +268,38 @@ def __new__(cls: type[CogMeta], *args: Any, **kwargs: Any) -> CogMeta:
             description = inspect.cleandoc(attrs.get("__doc__", ""))
         attrs["__cog_description__"] = description
 
-        commands = {}
-        listeners = {}
-        no_bot_cog = (
-            "Commands or listeners must not start with cog_ or bot_ (in method"
-            " {0.__name__}.{1})"
-        )
+        commands: dict[str, _BaseCommand | BridgeCommand] = {}
+        listeners: dict[str, Callable[..., Any]] = {}
 
         new_cls = super().__new__(cls, name, bases, attrs, **kwargs)
 
         for base in reversed(new_cls.__mro__):
-            for elem, value in base.__dict__.items():
-                if elem in commands:
-                    del commands[elem]
-                if elem in listeners:
-                    del listeners[elem]
-
-                if getattr(value, "parent", None) and isinstance(
-                    value, ApplicationCommand
-                ):
-                    # Skip commands if they are a part of a group
-                    continue
-
-                is_static_method = isinstance(value, staticmethod)
-                if is_static_method:
-                    value = value.__func__
-                if isinstance(value, _BaseCommand):
-                    if is_static_method:
-                        raise TypeError(
-                            f"Command in method {base}.{elem!r} must not be"
-                            " staticmethod."
-                        )
-                    if elem.startswith(("cog_", "bot_")):
-                        raise TypeError(no_bot_cog.format(base, elem))
-                    commands[elem] = value
-
-                # a test to see if this value is a BridgeCommand
-                if hasattr(value, "add_to") and not getattr(value, "parent", None):
-                    if is_static_method:
-                        raise TypeError(
-                            f"Command in method {base}.{elem!r} must not be"
-                            " staticmethod."
-                        )
-                    if elem.startswith(("cog_", "bot_")):
-                        raise TypeError(no_bot_cog.format(base, elem))
-
-                    commands[f"ext_{elem}"] = value.ext_variant
-                    commands[f"app_{elem}"] = value.slash_variant
-                    commands[elem] = value
-                    for cmd in getattr(value, "subcommands", []):
-                        commands[f"ext_{cmd.ext_variant.qualified_name}"] = (
-                            cmd.ext_variant
-                        )
-
-                if inspect.iscoroutinefunction(value):
-                    try:
-                        getattr(value, "__cog_listener__")
-                    except AttributeError:
-                        continue
-                    else:
-                        if elem.startswith(("cog_", "bot_")):
-                            raise TypeError(no_bot_cog.format(base, elem))
-                        listeners[elem] = value
+            new_commands, new_listeners = _process_attributes(base)
+            commands.update(new_commands)
+            listeners.update(new_listeners)
 
         new_cls.__cog_commands__ = list(commands.values())
 
-        listeners_as_list = []
-        for listener in listeners.values():
-            for listener_name in listener.__cog_listener_names__:
-                # I use __name__ instead of just storing the value, so I can inject
-                # the self attribute when the time comes to add them to the bot
-                listeners_as_list.append((listener_name, listener.__name__))
-
-        new_cls.__cog_listeners__ = listeners_as_list
+        new_cls.__cog_listeners__ = [
+            (listener_name, listener.__name__)
+            for listener in listeners.values()
+            for listener_name in listener.__cog_listener_names__
+        ]
 
         cmd_attrs = new_cls.__cog_settings__
 
         # Either update the command with the cog provided defaults or copy it.
         # r.e type ignore, type-checker complains about overriding a ClassVar
-        new_cls.__cog_commands__ = tuple(c._update_copy(cmd_attrs) if not hasattr(c, "add_to") else c for c in new_cls.__cog_commands__)  # type: ignore
-
-        name_filter = lambda c: (
-            "app"
-            if isinstance(c, ApplicationCommand)
-            else ("bridge" if not hasattr(c, "add_to") else "ext")
-        )
+        new_cls.__cog_commands__ = list(tuple(c._update_copy(cmd_attrs) if not _is_bridge_command(c) else c for c in new_cls.__cog_commands__))  # type: ignore
 
         lookup = {
-            f"{name_filter(cmd)}_{cmd.qualified_name}": cmd
+            f"{_name_filter(cmd)}_{cmd.qualified_name}": cmd
             for cmd in new_cls.__cog_commands__
         }
 
         # Update the Command instances dynamically as well
         for command in new_cls.__cog_commands__:
-            if (
-                isinstance(command, ApplicationCommand)
-                and not command.guild_ids
-                and new_cls.__cog_guild_ids__
-            ):
-                command.guild_ids = new_cls.__cog_guild_ids__
-
-            if not isinstance(command, SlashCommandGroup) and not hasattr(
-                command, "add_to"
-            ):
-                # ignore bridge commands
-                cmd = getattr(new_cls, command.callback.__name__, None)
-                if hasattr(cmd, "add_to"):
-                    setattr(
-                        cmd,
-                        f"{name_filter(command).replace('app', 'slash')}_variant",
-                        command,
-                    )
-                else:
-                    setattr(new_cls, command.callback.__name__, command)
-
-                parent = command.parent
-                if parent is not None:
-                    # Get the latest parent reference
-                    parent = lookup[f"{name_filter(command)}_{parent.qualified_name}"]  # type: ignore
-
-                    # Update our parent's reference to our self
-                    parent.remove_command(command.name)  # type: ignore
-                    parent.add_command(command)  # type: ignore
+            _update_command(command, new_cls.__cog_guild_ids__, lookup, new_cls)
 
         return new_cls
 
@@ -537,7 +573,7 @@ def _inject(self: CogT, bot) -> CogT:
         # we've added so far for some form of atomic loading.
 
         for index, command in enumerate(self.__cog_commands__):
-            if hasattr(command, "add_to"):
+            if _is_bridge_command(command):
                 bot.bridge_commands.append(command)
                 continue
 
@@ -582,7 +618,7 @@ def _eject(self, bot) -> None:
 
         try:
             for command in self.__cog_commands__:
-                if hasattr(command, "add_to"):
+                if _is_bridge_command(command):
                     bot.bridge_commands.remove(command)
                     continue
                 elif isinstance(command, ApplicationCommand):

discord/commands/core.py

@@ -726,6 +726,8 @@ class SlashCommand(ApplicationCommand):
 
     type = 1
 
+    parent: SlashCommandGroup | None
+
     def __new__(cls, *args, **kwargs) -> SlashCommand:
         self = super().__new__(cls)
 

discord/ext/bridge/core.py

@@ -184,6 +184,8 @@ class BridgeCommand:
         The prefix-based version of this bridge command.
     """
 
+    __bridge__: bool = True
+
     __special_attrs__ = ["slash_variant", "ext_variant", "parent"]
 
     def __init__(self, callback, **kwargs):