fix: update cooldown handling to support async operations

Author: Lumabots

discord/commands/core.py

@@ -333,10 +333,10 @@ def guild_only(self, value: bool) -> None:
                 InteractionContextType.private_channel,
             }
 
-    def _prepare_cooldowns(self, ctx: ApplicationContext):
+    async def _prepare_cooldowns(self, ctx: ApplicationContext):
         if self._buckets.valid:
             current = datetime.datetime.now().timestamp()
-            bucket = self._buckets.get_bucket(ctx, current)  # type: ignore # ctx instead of non-existent message
+            bucket = await self._buckets.get_bucket(ctx, current)  # type: ignore # ctx instead of non-existent message
 
             if bucket is not None:
                 retry_after = bucket.update_rate_limit(current)
@@ -360,7 +360,7 @@ async def prepare(self, ctx: ApplicationContext) -> None:
             await self._max_concurrency.acquire(ctx)  # type: ignore # ctx instead of non-existent message
 
         try:
-            self._prepare_cooldowns(ctx)
+            await self._prepare_cooldowns(ctx)
             await self.call_before_hooks(ctx)
         except:
             if self._max_concurrency is not None:

discord/ext/commands/context.py

@@ -311,7 +311,11 @@ def me(self) -> Member | ClientUser:
         message contexts, or when :meth:`Intents.guilds` is absent.
         """
         # bot.user will never be None at this point.
-        return self.guild.me if self.guild is not None and self.guild.me is not None else self.bot.user  # type: ignore
+        return (
+            self.guild.me
+            if self.guild is not None and self.guild.me is not None
+            else self.bot.user
+        )  # type: ignore
 
     @property
     def voice_client(self) -> VoiceProtocol | None:

discord/ext/commands/cooldowns.py

@@ -26,9 +26,10 @@
 from __future__ import annotations
 
 import asyncio
+import inspect
 import time
 from collections import deque
-from typing import TYPE_CHECKING, Any, Callable, Deque, TypeVar
+from typing import TYPE_CHECKING, Any, Awaitable, Callable, Deque, TypeVar
 
 import discord.abc
 from discord.enums import Enum
@@ -37,6 +38,8 @@
 from .errors import MaxConcurrencyReached
 
 if TYPE_CHECKING:
+    from ...commands import ApplicationContext
+    from ...ext.commands import Context
     from ...message import Message
 
 __all__ = (
@@ -60,31 +63,35 @@ class BucketType(Enum):
     category = 5
     role = 6
 
-    def get_key(self, msg: Message) -> Any:
+    def get_key(self, ctx: Context | ApplicationContext) -> Any:
         if self is BucketType.user:
-            return msg.author.id
+            return ctx.author.id
         elif self is BucketType.guild:
-            return (msg.guild or msg.author).id
+            return (ctx.guild or ctx.author).id
         elif self is BucketType.channel:
-            return msg.channel.id
+            return ctx.channel.id
         elif self is BucketType.member:
-            return (msg.guild and msg.guild.id), msg.author.id
+            return (ctx.guild and ctx.guild.id), ctx.author.id
         elif self is BucketType.category:
             return (
-                msg.channel.category.id
-                if isinstance(msg.channel, discord.abc.GuildChannel)
-                and msg.channel.category
-                else msg.channel.id
+                ctx.channel.category.id
+                if isinstance(ctx.channel, discord.abc.GuildChannel)
+                and ctx.channel.category
+                else ctx.channel.id
             )
         elif self is BucketType.role:
             # we return the channel id of a private-channel as there are only roles in guilds
             # and that yields the same result as for a guild with only the @everyone role
             # NOTE: PrivateChannel doesn't actually have an id attribute, but we assume we are
             # receiving a DMChannel or GroupChannel which inherit from PrivateChannel and do
-            return (msg.channel if isinstance(msg.channel, PrivateChannel) else msg.author.top_role).id  # type: ignore
+            return (
+                ctx.channel
+                if isinstance(ctx.channel, PrivateChannel)
+                else ctx.author.top_role
+            ).id  # type: ignore
 
-    def __call__(self, msg: Message) -> Any:
-        return self.get_key(msg)
+    def __call__(self, ctx: Context | ApplicationContext) -> Any:
+        return self.get_key(ctx)
 
 
 class Cooldown:
@@ -208,14 +215,14 @@ class CooldownMapping:
     def __init__(
         self,
         original: Cooldown | None,
-        type: Callable[[Message], Any],
+        type: Callable[[Context | ApplicationContext], Any],
     ) -> None:
         if not callable(type):
             raise TypeError("Cooldown type must be a BucketType or callable")
 
         self._cache: dict[Any, Cooldown] = {}
         self._cooldown: Cooldown | None = original
-        self._type: Callable[[Message], Any] = type
+        self._type: Callable[[Context | ApplicationContext], Any] = type
 
     def copy(self) -> CooldownMapping:
         ret = CooldownMapping(self._cooldown, self._type)
@@ -227,15 +234,15 @@ def valid(self) -> bool:
         return self._cooldown is not None
 
     @property
-    def type(self) -> Callable[[Message], Any]:
+    def type(self) -> Callable[[Context | ApplicationContext], Any]:
         return self._type
 
     @classmethod
     def from_cooldown(cls: type[C], rate, per, type) -> C:
         return cls(Cooldown(rate, per), type)
 
-    def _bucket_key(self, msg: Message) -> Any:
-        return self._type(msg)
+    def _bucket_key(self, ctx: Context | ApplicationContext) -> Any:
+        return self._type(ctx)
 
     def _verify_cache_integrity(self, current: float | None = None) -> None:
         # we want to delete all cache objects that haven't been used
@@ -246,37 +253,45 @@ def _verify_cache_integrity(self, current: float | None = None) -> None:
         for k in dead_keys:
             del self._cache[k]
 
-    def create_bucket(self, message: Message) -> Cooldown:
+    async def create_bucket(self, ctx: Context | ApplicationContext) -> Cooldown:
         return self._cooldown.copy()  # type: ignore
 
-    def get_bucket(self, message: Message, current: float | None = None) -> Cooldown:
+    async def get_bucket(
+        self, ctx: Context | ApplicationContext, current: float | None = None
+    ) -> Cooldown:
         if self._type is BucketType.default:
             return self._cooldown  # type: ignore
 
         self._verify_cache_integrity(current)
-        key = self._bucket_key(message)
+        key = self._bucket_key(ctx)
         if key not in self._cache:
-            bucket = self.create_bucket(message)
+            bucket = await self.create_bucket(ctx)
             if bucket is not None:
                 self._cache[key] = bucket
         else:
             bucket = self._cache[key]
 
         return bucket
 
-    def update_rate_limit(
-        self, message: Message, current: float | None = None
+    async def update_rate_limit(
+        self, ctx: Context | ApplicationContext, current: float | None = None
     ) -> float | None:
-        bucket = self.get_bucket(message, current)
+        bucket = await self.get_bucket(ctx, current)
         return bucket.update_rate_limit(current)
 
 
 class DynamicCooldownMapping(CooldownMapping):
     def __init__(
-        self, factory: Callable[[Message], Cooldown], type: Callable[[Message], Any]
+        self,
+        factory: Callable[
+            [Context | ApplicationContext], Cooldown | Awaitable[Cooldown]
+        ],
+        type: Callable[[Context | ApplicationContext], Any],
     ) -> None:
         super().__init__(None, type)
-        self._factory: Callable[[Message], Cooldown] = factory
+        self._factory: Callable[
+            [Context | ApplicationContext], Cooldown | Awaitable[Cooldown]
+        ] = factory
 
     def copy(self) -> DynamicCooldownMapping:
         ret = DynamicCooldownMapping(self._factory, self._type)
@@ -287,8 +302,16 @@ def copy(self) -> DynamicCooldownMapping:
     def valid(self) -> bool:
         return True
 
-    def create_bucket(self, message: Message) -> Cooldown:
-        return self._factory(message)
+    async def create_bucket(self, ctx: Context | ApplicationContext) -> Cooldown:
+        from ...ext.commands import Context
+
+        if isinstance(ctx, Context):
+            result = self._factory(ctx.message)
+        else:
+            result = self._factory(ctx)
+        if inspect.isawaitable(result):
+            return await result
+        return result
 
 
 class _Semaphore:

discord/ext/commands/core.py

@@ -33,6 +33,7 @@
 from typing import (
     TYPE_CHECKING,
     Any,
+    Awaitable,
     Callable,
     Generator,
     Generic,
@@ -69,6 +70,7 @@
 if TYPE_CHECKING:
     from typing_extensions import Concatenate, ParamSpec, TypeGuard
 
+    from discord import ApplicationContext
     from discord.message import Message
 
     from ._types import Check, Coro, CoroFunc, Error, Hook
@@ -397,7 +399,9 @@ def __init__(
 
         # bandaid for the fact that sometimes parent can be the bot instance
         parent = kwargs.get("parent")
-        self.parent: GroupMixin | None = parent if isinstance(parent, _BaseCommand) else None  # type: ignore
+        self.parent: GroupMixin | None = (
+            parent if isinstance(parent, _BaseCommand) else None
+        )  # type: ignore
 
         self._before_invoke: Hook | None = None
         try:
@@ -850,11 +854,11 @@ async def call_after_hooks(self, ctx: Context) -> None:
         if hook is not None:
             await hook(ctx)
 
-    def _prepare_cooldowns(self, ctx: Context) -> None:
+    async def _prepare_cooldowns(self, ctx: Context) -> None:
         if self._buckets.valid:
             dt = ctx.message.edited_at or ctx.message.created_at
             current = dt.replace(tzinfo=datetime.timezone.utc).timestamp()
-            bucket = self._buckets.get_bucket(ctx.message, current)
+            bucket = await self._buckets.get_bucket(ctx, current)
             if bucket is not None:
                 retry_after = bucket.update_rate_limit(current)
                 if retry_after:
@@ -875,9 +879,9 @@ async def prepare(self, ctx: Context) -> None:
         try:
             if self.cooldown_after_parsing:
                 await self._parse_arguments(ctx)
-                self._prepare_cooldowns(ctx)
+                await self._prepare_cooldowns(ctx)
             else:
-                self._prepare_cooldowns(ctx)
+                await self._prepare_cooldowns(ctx)
                 await self._parse_arguments(ctx)
 
             await self.call_before_hooks(ctx)
@@ -1204,7 +1208,9 @@ async def can_run(self, ctx: Context) -> bool:
                 # since we have no checks, then we just return True.
                 return True
 
-            return await discord.utils.async_all(predicate(ctx) for predicate in predicates)  # type: ignore
+            return await discord.utils.async_all(
+                predicate(ctx) for predicate in predicates
+            )  # type: ignore
         finally:
             ctx.command = original
 
@@ -2353,36 +2359,23 @@ def decorator(func: Command | CoroFunc) -> Command | CoroFunc:
 
 
 def dynamic_cooldown(
-    cooldown: BucketType | Callable[[Message], Any],
+    cooldown: Callable[
+        [Context | ApplicationContext], Cooldown | Awaitable[Cooldown] | None
+    ],
     type: BucketType = BucketType.default,
 ) -> Callable[[T], T]:
-    """A decorator that adds a dynamic cooldown to a command
-
-    This differs from :func:`.cooldown` in that it takes a function that
-    accepts a single parameter of type :class:`.discord.Message` and must
-    return a :class:`.Cooldown` or ``None``. If ``None`` is returned then
-    that cooldown is effectively bypassed.
-
-    A cooldown allows a command to only be used a specific amount
-    of times in a specific time frame. These cooldowns can be based
-    either on a per-guild, per-channel, per-user, per-role or global basis.
-    Denoted by the third argument of ``type`` which must be of enum
-    type :class:`.BucketType`.
-
-    If a cooldown is triggered, then :exc:`.CommandOnCooldown` is triggered in
-    :func:`.on_command_error` and the local error handler.
-
-    A command can only have a single cooldown.
+    """A decorator that adds a dynamic cooldown to a command.
 
-    .. versionadded:: 2.0
+    This supports both sync and async cooldown factories and accepts either
+    a :class:`discord.Message` or :class:`discord.ApplicationContext`.
 
     Parameters
     ----------
-    cooldown: Callable[[:class:`.discord.Message`], Optional[:class:`.Cooldown`]]
-        A function that takes a message and returns a cooldown that will
-        apply to this invocation or ``None`` if the cooldown should be bypassed.
-    type: :class:`.BucketType`
-        The type of cooldown to have.
+    cooldown: Callable[[Union[Message, ApplicationContext]], Union[Cooldown, Awaitable[Cooldown], None]]
+        A function that takes a message or context and returns a cooldown
+        to apply for that invocation or ``None`` to bypass.
+    type: :class:`BucketType`
+        The cooldown bucket type (e.g. per-user, per-channel).
     """
     if not callable(cooldown):
         raise TypeError("A callable must be provided")