Add get_hash to CommandTree

discord/app_commands/tree.py

@@ -25,6 +25,7 @@
 from __future__ import annotations
 import logging
 import inspect
+from hashlib import blake2b
 
 from typing import (
     Any,
@@ -62,7 +63,7 @@
 from .translator import Translator, locale_str
 from ..errors import ClientException, HTTPException
 from ..enums import AppCommandType, InteractionType
-from ..utils import MISSING, _get_as_snowflake, _is_submodule, _shorten
+from ..utils import MISSING, _get_as_snowflake, _is_submodule, _shorten, _to_json
 from .._types import ClientT
 
 
@@ -1076,6 +1077,17 @@ async def set_translator(self, translator: Optional[Translator]) -> None:
             await translator.load()
             self._state._translator = translator
 
+    async def _get_payload(self, *, guild: Optional[Snowflake] = None) -> List[Dict[str, Any]]:
+        commands = self._get_all_commands(guild=guild)
+
+        translator = self.translator
+        if translator:
+            payload = [await command.get_translated_payload(self, translator) for command in commands]
+        else:
+            payload = [command.to_dict(self) for command in commands]
+
+        return payload
+
     async def sync(self, *, guild: Optional[Snowflake] = None) -> List[AppCommand]:
         """|coro|
 
@@ -1116,13 +1128,7 @@ async def sync(self, *, guild: Optional[Snowflake] = None) -> List[AppCommand]:
         if self.client.application_id is None:
             raise MissingApplicationID
 
-        commands = self._get_all_commands(guild=guild)
-
-        translator = self.translator
-        if translator:
-            payload = [await command.get_translated_payload(self, translator) for command in commands]
-        else:
-            payload = [command.to_dict(self) for command in commands]
+        payload = await self._get_payload(guild=guild)
 
         try:
             if guild is None:
@@ -1131,7 +1137,7 @@ async def sync(self, *, guild: Optional[Snowflake] = None) -> List[AppCommand]:
                 data = await self._http.bulk_upsert_guild_commands(self.client.application_id, guild.id, payload=payload)
         except HTTPException as e:
             if e.status == 400 and e.code == 50035:
-                raise CommandSyncFailure(e, commands) from None
+                raise CommandSyncFailure(e, self._get_all_commands(guild=guild)) from None
             raise
 
         return [AppCommand(data=d, state=self._state) for d in data]
@@ -1315,3 +1321,22 @@ async def _call(self, interaction: Interaction[ClientT]) -> None:
         else:
             if not interaction.command_failed:
                 self.client.dispatch('app_command_completion', interaction, command)
+
+    async def get_hash(self, *, guild: Optional[Snowflake] = None) -> str:
+        """|coro|
+
+        Returns a hash for tree's state, either for the global tree
+        if no guild is provided, or the guild specific portions of
+        the tree if a guild is provided.
+
+        This can be used to avoid uneccessary syncing.
+
+        Parameters
+        -----------
+        guild: Optional[:class:`~discord.abc.Snowflake`]
+        """
+        payload = await self._get_payload(guild=guild)
+        # versioning allows the method to be changed in the future
+        # blake2 is the fastest collision resistant hash guaranteed
+        # to be available in the standard library at time of writing.
+        return "v1:" + blake2b(_to_json(payload).encode()).hexdigest()