feat: ✨ Allow usage of functools.partial as slash or ext command callback

CHANGELOG.md

@@ -51,6 +51,8 @@ These changes are available on the `master` branch, but have not yet been releas
   ([#2564](https://github.com/Pycord-Development/pycord/pull/2564))
 - Added ability to change the API's base URL with `Route.API_BASE_URL`.
   ([#2714](https://github.com/Pycord-Development/pycord/pull/2714))
+- Added the ability to use `functools.partial` as `Command` and `SlashCommand`
+  callbacks. ([#2724](https://github.com/Pycord-Development/pycord/pull/2724))
 
 ### Fixed
 

discord/cog.py

@@ -31,6 +31,7 @@
 import pathlib
 import sys
 import types
+from functools import partial
 from typing import Any, Callable, ClassVar, Generator, Mapping, TypeVar, overload
 
 import discord.utils
@@ -256,16 +257,22 @@ def __new__(cls: type[CogMeta], *args: Any, **kwargs: Any) -> CogMeta:
             if not isinstance(command, SlashCommandGroup) and not hasattr(
                 command, "add_to"
             ):
+                actual_callback = (
+                    command.callback.func
+                    if isinstance(command.callback, partial)
+                    else command.callback
+                )
+
                 # ignore bridge commands
-                cmd = getattr(new_cls, command.callback.__name__, None)
+                cmd = getattr(new_cls, actual_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)
+                    setattr(new_cls, actual_callback.__name__, command)
 
                 parent = command.parent
                 if parent is not None:

discord/commands/core.py

@@ -192,6 +192,8 @@ class ApplicationCommand(_BaseCommand, Generic[CogT, P, T]):
     def __init__(self, func: Callable, **kwargs) -> None:
         from ..ext.commands.cooldowns import BucketType, CooldownMapping, MaxConcurrency
 
+        actual_func = func if not isinstance(func, functools.partial) else func.func
+
         cooldown = getattr(func, "__commands_cooldown__", kwargs.get("cooldown"))
 
         if cooldown is None:
@@ -214,7 +216,7 @@ def __init__(self, func: Callable, **kwargs) -> None:
         self._callback = None
         self.module = None
 
-        self.name: str = kwargs.get("name", func.__name__)
+        self.name: str = kwargs.get("name", actual_func.__name__)
 
         try:
             checks = func.__commands_checks__
@@ -483,7 +485,13 @@ async def dispatch_error(self, ctx: ApplicationContext, error: Exception) -> Non
             ctx.bot.dispatch("application_command_error", ctx, error)
 
     def _get_signature_parameters(self):
-        return OrderedDict(inspect.signature(self.callback).parameters)
+        params = OrderedDict(inspect.signature(self.callback).parameters)
+
+        if isinstance(self.callback, functools.partial):
+            for param in self.callback.keywords:
+                params.pop(param, None)
+
+        return params
 
     def error(self, coro):
         """A decorator that registers a coroutine as a local error handler.

discord/ext/commands/core.py

@@ -153,7 +153,9 @@ def get_signature_parameters(
             raise TypeError("Unparameterized Greedy[...] is disallowed in signature.")
 
         params[name] = parameter.replace(annotation=annotation)
-
+    if isinstance(function, functools.partial):
+        for param in function.keywords:
+            params.pop(param, None)
     return params
 
 
@@ -328,7 +330,9 @@ def __init__(
         if not asyncio.iscoroutinefunction(func):
             raise TypeError("Callback must be a coroutine.")
 
-        name = kwargs.get("name") or func.__name__
+        actual_func = func if not isinstance(func, functools.partial) else func.func
+
+        name = kwargs.get("name", actual_func.__name__)
         if not isinstance(name, str):
             raise TypeError("Name of a command must be a string.")
         self.name: str = name