Use typing.Protocol instead of abc.ABCMeta

discord/abc.py

@@ -22,10 +22,12 @@
 DEALINGS IN THE SOFTWARE.
 """
 
-import abc
+from __future__ import annotations
+
 import sys
 import copy
 import asyncio
+from typing import TYPE_CHECKING, Optional, Protocol, runtime_checkable
 
 from .iterators import HistoryIterator
 from .context_managers import Typing
@@ -39,13 +41,22 @@
 from .voice_client import VoiceClient, VoiceProtocol
 from . import utils
 
+if TYPE_CHECKING:
+    from datetime import datetime
+
+    from .user import ClientUser
+
+
 class _Undefined:
     def __repr__(self):
         return 'see-below'
 
+
 _undefined = _Undefined()
 
-class Snowflake(metaclass=abc.ABCMeta):
+
+@runtime_checkable
+class Snowflake(Protocol):
     """An ABC that details the common operations on a Discord model.
 
     Almost all :ref:`Discord models <discord_api_models>` meet this
@@ -60,27 +71,16 @@ class Snowflake(metaclass=abc.ABCMeta):
         The model's unique ID.
     """
     __slots__ = ()
+    id: int
 
     @property
-    @abc.abstractmethod
-    def created_at(self):
+    def created_at(self) -> datetime:
         """:class:`datetime.datetime`: Returns the model's creation time as a naive datetime in UTC."""
         raise NotImplementedError
 
-    @classmethod
-    def __subclasshook__(cls, C):
-        if cls is Snowflake:
-            mro = C.__mro__
-            for attr in ('created_at', 'id'):
-                for base in mro:
-                    if attr in base.__dict__:
-                        break
-                else:
-                    return NotImplemented
-            return True
-        return NotImplemented
 
-class User(metaclass=abc.ABCMeta):
+@runtime_checkable
+class User(Snowflake, Protocol):
     """An ABC that details the common operations on a Discord user.
 
     The following implement this ABC:
@@ -104,35 +104,24 @@ class User(metaclass=abc.ABCMeta):
     """
     __slots__ = ()
 
+    name: str
+    discriminator: str
+    avatar: Optional[str]
+    bot: bool
+
     @property
-    @abc.abstractmethod
-    def display_name(self):
+    def display_name(self) -> str:
         """:class:`str`: Returns the user's display name."""
         raise NotImplementedError
 
     @property
-    @abc.abstractmethod
-    def mention(self):
+    def mention(self) -> str:
         """:class:`str`: Returns a string that allows you to mention the given user."""
         raise NotImplementedError
 
-    @classmethod
-    def __subclasshook__(cls, C):
-        if cls is User:
-            if Snowflake.__subclasshook__(C) is NotImplemented:
-                return NotImplemented
-
-            mro = C.__mro__
-            for attr in ('display_name', 'mention', 'name', 'avatar', 'discriminator', 'bot'):
-                for base in mro:
-                    if attr in base.__dict__:
-                        break
-                else:
-                    return NotImplemented
-            return True
-        return NotImplemented
 
-class PrivateChannel(metaclass=abc.ABCMeta):
+@runtime_checkable
+class PrivateChannel(Snowflake, Protocol):
     """An ABC that details the common operations on a private Discord channel.
 
     The following implement this ABC:
@@ -149,18 +138,8 @@ class PrivateChannel(metaclass=abc.ABCMeta):
     """
     __slots__ = ()
 
-    @classmethod
-    def __subclasshook__(cls, C):
-        if cls is PrivateChannel:
-            if Snowflake.__subclasshook__(C) is NotImplemented:
-                return NotImplemented
+    me: ClientUser
 
-            mro = C.__mro__
-            for base in mro:
-                if 'me' in base.__dict__:
-                    return True
-            return NotImplemented
-        return NotImplemented
 
 class _Overwrites:
     __slots__ = ('id', 'allow', 'deny', 'type')
@@ -179,7 +158,8 @@ def _asdict(self):
             'type': self.type,
         }
 
-class GuildChannel:
+
+class GuildChannel(Protocol):
     """An ABC that details the common operations on a Discord guild channel.
 
     The following implement this ABC:
@@ -190,6 +170,11 @@ class GuildChannel:
 
     This ABC must also implement :class:`~discord.abc.Snowflake`.
 
+    Note
+    ----
+    This ABC is not decorated with :func:`typing.runtime_checkable`, so will fail :func:`isinstance`/:func:`issubclass`
+    checks.
+
     Attributes
     -----------
     name: :class:`str`
@@ -826,14 +811,13 @@ async def move(self, **kwargs):
         lock_permissions = kwargs.get('sync_permissions', False)
         reason = kwargs.get('reason')
         for index, channel in enumerate(channels):
-            d = { 'id': channel.id, 'position': index }
+            d = {'id': channel.id, 'position': index}
             if parent_id is not ... and channel.id == self.id:
                 d.update(parent_id=parent_id, lock_permissions=lock_permissions)
             payload.append(d)
 
         await self._state.http.bulk_channel_update(self.guild.id, payload, reason=reason)
 
-
     async def create_invite(self, *, reason=None, **fields):
         """|coro|
 
@@ -908,7 +892,8 @@ async def invites(self):
 
         return result
 
-class Messageable(metaclass=abc.ABCMeta):
+
+class Messageable(Protocol):
     """An ABC that details the common operations on a model that can send messages.
 
     The following implement this ABC:
@@ -919,11 +904,16 @@ class Messageable(metaclass=abc.ABCMeta):
     - :class:`~discord.User`
     - :class:`~discord.Member`
     - :class:`~discord.ext.commands.Context`
+
+
+    Note
+    ----
+    This ABC is not decorated with :func:`typing.runtime_checkable`, so will fail :func:`isinstance`/:func:`issubclass`
+    checks.
     """
 
     __slots__ = ()
 
-    @abc.abstractmethod
     async def _get_channel(self):
         raise NotImplementedError
 
@@ -1060,8 +1050,8 @@ async def send(self, content=None, *, tts=False, embed=None, file=None,
                     f.close()
         else:
             data = await state.http.send_message(channel.id, content, tts=tts, embed=embed,
-                                                                      nonce=nonce, allowed_mentions=allowed_mentions,
-                                                                      message_reference=reference)
+                                                 nonce=nonce, allowed_mentions=allowed_mentions,
+                                                 message_reference=reference)
 
         ret = state.create_message(channel=channel, data=data)
         if delete_after is not None:
@@ -1213,21 +1203,25 @@ def history(self, *, limit=100, before=None, after=None, around=None, oldest_fir
         """
         return HistoryIterator(self, limit=limit, before=before, after=after, around=around, oldest_first=oldest_first)
 
-class Connectable(metaclass=abc.ABCMeta):
+
+class Connectable(Protocol):
     """An ABC that details the common operations on a channel that can
     connect to a voice server.
 
     The following implement this ABC:
 
     - :class:`~discord.VoiceChannel`
+
+    Note
+    ----
+    This ABC is not decorated with :func:`typing.runtime_checkable`, so will fail :func:`isinstance`/:func:`issubclass`
+    checks.
     """
     __slots__ = ()
 
-    @abc.abstractmethod
     def _get_voice_client_key(self):
         raise NotImplementedError
 
-    @abc.abstractmethod
     def _get_voice_state_pair(self):
         raise NotImplementedError
 
@@ -1286,6 +1280,6 @@ async def connect(self, *, timeout=60.0, reconnect=True, cls=VoiceClient):
             except Exception:
                 # we don't care if disconnect failed because connection failed
                 pass
-            raise # re-raise
+            raise  # re-raise
 
         return voice