[commands] Add guild-based permission checks

discord/ext/commands/core.py

@@ -56,6 +56,8 @@ __all__ = (
     'guild_only',
     'is_owner',
     'is_nsfw',
+    'has_guild_permissions',
+    'bot_has_guild_permissions'
 )
 
 def wrap_callback(coro):
@@ -1497,6 +1499,9 @@ def has_permissions(**perms):
     """A :func:`.check` that is added that checks if the member has all of
     the permissions necessary.
     
+    Note that this check operates on the current channel permissions, not the
+    guild wide permissions.
+
     The permissions passed in must be exactly like the properties shown under
     :class:`.discord.Permissions`.
 
@@ -1553,6 +1558,49 @@ def bot_has_permissions(**perms):
 
     return check(predicate)
 
+def has_guild_permissions(**perms):
+    """Similar to :func:`.has_permissions`, but operates on guild wide
+    permissions instead of the current channel permissions.
+    
+    If this check is called in a DM context, it will raise an
+    exception, :exc:`.NoPrivateMessage`.
+   
+    .. versionadded:: 1.3.0
+    """
+    def predicate(ctx):
+        if not ctx.guild:
+            raise NoPrivateMessage
+            
+        permissions = ctx.author.guild_permissions
+        missing = [perm for perm, value in perms.items() if getattr(permissions, perm, None) != value]
+        
+        if not missing:
+            return True
+        
+        raise MissingPermissions(missing)
+    
+    return check(predicate)
+
+def bot_has_guild_permissions(**perms):
+    """Similar to :func:`.has_guild_permissions`, but checks the bot
+    members guild permissions.
+    
+    .. versionadded:: 1.3.0
+    """
+    def predicate(ctx):
+        if not ctx.guild:
+            raise NoPrivateMessage
+        
+        permissions = ctx.me.guild_permissions
+        missing = [perm for perm, value in perms.items() if getattr(permissions, perm, None) != value]
+        
+        if not missing:
+            return True
+        
+        raise BotMissingPermissions(missing)
+    
+    return check(predicate)
+
 def dm_only():
     """A :func:`.check` that indicates this command must only be used in a
     DM context. Only private messages are allowed when