[commands] Add subclasses of BadArgument for converters

discord/ext/commands/converter.py

@@ -30,7 +30,7 @@ import typing
 
 import discord
 
-from .errors import BadArgument, NoPrivateMessage
+from .errors import *
 
 __all__ = (
     'Converter',
@@ -119,6 +119,9 @@ class MemberConverter(IDConverter):
     3. Lookup by name#discrim
     4. Lookup by name
     5. Lookup by nickname
+
+    .. versionchanged:: 1.5
+         Raise :exc:`.MemberNotFound` instead of generic :exc:`.BadArgument`
     """
 
     async def convert(self, ctx, argument):
@@ -140,7 +143,7 @@ class MemberConverter(IDConverter):
                 result = _get_from_guilds(bot, 'get_member', user_id)
 
         if result is None:
-            raise BadArgument('Member "{}" not found'.format(argument))
+            raise MemberNotFound(argument)
 
         return result
 
@@ -155,6 +158,9 @@ class UserConverter(IDConverter):
     2. Lookup by mention.
     3. Lookup by name#discrim
     4. Lookup by name
+
+    .. versionchanged:: 1.5
+         Raise :exc:`.UserNotFound` instead of generic :exc:`.BadArgument`
     """
     async def convert(self, ctx, argument):
         match = self._get_id_match(argument) or re.match(r'<@!?([0-9]+)>$', argument)
@@ -185,7 +191,7 @@ class UserConverter(IDConverter):
             result = discord.utils.find(predicate, state._users.values())
 
         if result is None:
-            raise BadArgument('User "{}" not found'.format(argument))
+            raise UserNotFound(argument)
 
         return result
 
@@ -199,6 +205,9 @@ class MessageConverter(Converter):
     1. Lookup by "{channel ID}-{message ID}" (retrieved by shift-clicking on "Copy ID")
     2. Lookup by message ID (the message **must** be in the context channel)
     3. Lookup by message URL
+
+    .. versionchanged:: 1.5
+         Raise :exc:`.ChannelNotFound`, `MessageNotFound` or `ChannelNotReadable` instead of generic :exc:`.BadArgument`
     """
 
     async def convert(self, ctx, argument):
@@ -210,7 +219,7 @@ class MessageConverter(Converter):
         )
         match = id_regex.match(argument) or link_regex.match(argument)
         if not match:
-            raise BadArgument('Message "{msg}" not found.'.format(msg=argument))
+            raise MessageNotFound(argument)
         message_id = int(match.group("message_id"))
         channel_id = match.group("channel_id")
         message = ctx.bot._connection._get_message(message_id)
@@ -218,13 +227,13 @@ class MessageConverter(Converter):
             return message
         channel = ctx.bot.get_channel(int(channel_id)) if channel_id else ctx.channel
         if not channel:
-            raise BadArgument('Channel "{channel}" not found.'.format(channel=channel_id))
+            raise ChannelNotFound(channel_id)
         try:
             return await channel.fetch_message(message_id)
         except discord.NotFound:
-            raise BadArgument('Message "{msg}" not found.'.format(msg=argument))
+            raise MessageNotFound(argument)
         except discord.Forbidden:
-            raise BadArgument("Can't read messages in {channel}".format(channel=channel.mention))
+            raise ChannelNotReadable(channel)
 
 class TextChannelConverter(IDConverter):
     """Converts to a :class:`~discord.TextChannel`.
@@ -237,6 +246,9 @@ class TextChannelConverter(IDConverter):
     1. Lookup by ID.
     2. Lookup by mention.
     3. Lookup by name
+
+    .. versionchanged:: 1.5
+         Raise :exc:`.ChannelNotFound` instead of generic :exc:`.BadArgument`
     """
     async def convert(self, ctx, argument):
         bot = ctx.bot
@@ -261,7 +273,7 @@ class TextChannelConverter(IDConverter):
                 result = _get_from_guilds(bot, 'get_channel', channel_id)
 
         if not isinstance(result, discord.TextChannel):
-            raise BadArgument('Channel "{}" not found.'.format(argument))
+            raise ChannelNotFound(argument)
 
         return result
 
@@ -276,6 +288,9 @@ class VoiceChannelConverter(IDConverter):
     1. Lookup by ID.
     2. Lookup by mention.
     3. Lookup by name
+
+    .. versionchanged:: 1.5
+         Raise :exc:`.ChannelNotFound` instead of generic :exc:`.BadArgument`
     """
     async def convert(self, ctx, argument):
         bot = ctx.bot
@@ -299,7 +314,7 @@ class VoiceChannelConverter(IDConverter):
                 result = _get_from_guilds(bot, 'get_channel', channel_id)
 
         if not isinstance(result, discord.VoiceChannel):
-            raise BadArgument('Channel "{}" not found.'.format(argument))
+            raise ChannelNotFound(argument)
 
         return result
 
@@ -314,6 +329,9 @@ class CategoryChannelConverter(IDConverter):
     1. Lookup by ID.
     2. Lookup by mention.
     3. Lookup by name
+
+    .. versionchanged:: 1.5
+         Raise :exc:`.ChannelNotFound` instead of generic :exc:`.BadArgument`
     """
     async def convert(self, ctx, argument):
         bot = ctx.bot
@@ -338,7 +356,7 @@ class CategoryChannelConverter(IDConverter):
                 result = _get_from_guilds(bot, 'get_channel', channel_id)
 
         if not isinstance(result, discord.CategoryChannel):
-            raise BadArgument('Channel "{}" not found.'.format(argument))
+            raise ChannelNotFound(argument)
 
         return result
 
@@ -355,6 +373,9 @@ class ColourConverter(Converter):
     - Any of the ``classmethod`` in :class:`Colour`
 
         - The ``_`` in the name can be optionally replaced with spaces.
+
+    .. versionchanged:: 1.5
+         Raise :exc:`.BadColourArgument` instead of generic :exc:`.BadArgument`
     """
     async def convert(self, ctx, argument):
         arg = argument.replace('0x', '').lower()
@@ -364,13 +385,13 @@ class ColourConverter(Converter):
         try:
             value = int(arg, base=16)
             if not (0 <= value <= 0xFFFFFF):
-                raise BadArgument('Colour "{}" is invalid.'.format(arg))
+                raise BadColourArgument(arg)
             return discord.Colour(value=value)
         except ValueError:
             arg = arg.replace(' ', '_')
             method = getattr(discord.Colour, arg, None)
             if arg.startswith('from_') or method is None or not inspect.ismethod(method):
-                raise BadArgument('Colour "{}" is invalid.'.format(arg))
+                raise BadColourArgument(arg)
             return method()
 
 ColorConverter = ColourConverter
@@ -386,6 +407,9 @@ class RoleConverter(IDConverter):
     1. Lookup by ID.
     2. Lookup by mention.
     3. Lookup by name
+
+    .. versionchanged:: 1.5
+         Raise :exc:`.RoleNotFound` instead of generic :exc:`.BadArgument`
     """
     async def convert(self, ctx, argument):
         guild = ctx.guild
@@ -399,7 +423,7 @@ class RoleConverter(IDConverter):
             result = discord.utils.get(guild._roles.values(), name=argument)
 
         if result is None:
-            raise BadArgument('Role "{}" not found.'.format(argument))
+            raise RoleNotFound(argument)
         return result
 
 class GameConverter(Converter):
@@ -411,13 +435,16 @@ class InviteConverter(Converter):
     """Converts to a :class:`~discord.Invite`.
 
     This is done via an HTTP request using :meth:`.Bot.fetch_invite`.
+
+    .. versionchanged:: 1.5
+         Raise :exc:`.BadInviteArgument` instead of generic :exc:`.BadArgument`
     """
     async def convert(self, ctx, argument):
         try:
             invite = await ctx.bot.fetch_invite(argument)
             return invite
         except Exception as exc:
-            raise BadArgument('Invite is invalid or expired') from exc
+            raise BadInviteArgument() from exc
 
 class EmojiConverter(IDConverter):
     """Converts to a :class:`~discord.Emoji`.
@@ -430,6 +457,9 @@ class EmojiConverter(IDConverter):
     1. Lookup by ID.
     2. Lookup by extracting ID from the emoji.
     3. Lookup by name
+
+    .. versionchanged:: 1.5
+         Raise :exc:`.EmojiNotFound` instead of generic :exc:`.BadArgument`
     """
     async def convert(self, ctx, argument):
         match = self._get_id_match(argument) or re.match(r'<a?:[a-zA-Z0-9\_]+:([0-9]+)>$', argument)
@@ -455,7 +485,7 @@ class EmojiConverter(IDConverter):
                 result = discord.utils.get(bot.emojis, id=emoji_id)
 
         if result is None:
-            raise BadArgument('Emoji "{}" not found.'.format(argument))
+            raise EmojiNotFound(argument)
 
         return result
 
@@ -463,6 +493,9 @@ class PartialEmojiConverter(Converter):
     """Converts to a :class:`~discord.PartialEmoji`.
 
     This is done by extracting the animated flag, name and ID from the emoji.
+
+    .. versionchanged:: 1.5
+         Raise :exc:`.PartialEmojiConversionFailure` instead of generic :exc:`.BadArgument`
     """
     async def convert(self, ctx, argument):
         match = re.match(r'<(a?):([a-zA-Z0-9\_]+):([0-9]+)>$', argument)
@@ -475,7 +508,7 @@ class PartialEmojiConverter(Converter):
             return discord.PartialEmoji.with_state(ctx.bot._connection, animated=emoji_animated, name=emoji_name,
                                                    id=emoji_id)
 
-        raise BadArgument('Couldn\'t convert "{}" to PartialEmoji.'.format(argument))
+        raise PartialEmojiConversionFailure(argument)
 
 class clean_content(Converter):
     """Converts the argument to mention scrubbed version of

discord/ext/commands/core.py

@@ -107,7 +107,7 @@ def _convert_to_bool(argument):
     elif lowered in ('no', 'n', 'false', 'f', '0', 'disable', 'off'):
         return False
     else:
-        raise BadArgument(lowered + ' is not a recognised boolean option')
+        raise BadBooleanArgument(lowered)
 
 class _CaseInsensitiveDict(dict):
     def __contains__(self, k):

discord/ext/commands/errors.py

@@ -43,6 +43,17 @@ __all__ = (
     'CommandOnCooldown',
     'MaxConcurrencyReached',
     'NotOwner',
+    'MessageNotFound',
+    'MemberNotFound',
+    'UserNotFound',
+    'ChannelNotFound',
+    'ChannelNotReadable',
+    'BadColourArgument',
+    'RoleNotFound',
+    'BadInviteArgument',
+    'EmojiNotFound',
+    'PartialEmojiConversionFailure',
+    'BadBooleanArgument',
     'MissingRole',
     'BotMissingRole',
     'MissingAnyRole',
@@ -202,6 +213,182 @@ class NotOwner(CheckFailure):
     """
     pass
 
+class MemberNotFound(BadArgument):
+    """Exception raised when the member provided was not found in the bot's
+    cache.
+
+    This inherits from :exc:`BadArgument`
+
+    .. versionadded:: 1.5
+
+    Attributes
+    -----------
+    argument: :class:`str`
+        The member supplied by the caller that was not found
+    """
+    def __init__(self, argument):
+        self.argument = argument
+        super().__init__('Member "{}" not found.'.format(argument))
+
+class UserNotFound(BadArgument):
+    """Exception raised when the user provided was not found in the bot's
+    cache.
+
+    This inherits from :exc:`BadArgument`
+
+    .. versionadded:: 1.5
+
+    Attributes
+    -----------
+    argument: :class:`str`
+        The user supplied by the caller that was not found
+    """
+    def __init__(self, argument):
+        self.argument = argument
+        super().__init__('User "{}" not found.'.format(argument))
+
+class MessageNotFound(BadArgument):
+    """Exception raised when the message provided was not found in the channel.
+
+    This inherits from :exc:`BadArgument`
+
+    .. versionadded:: 1.5
+
+    Attributes
+    -----------
+    argument: :class:`str`
+        The message supplied by the caller that was not found
+    """
+    def __init__(self, argument):
+        self.argument = argument
+        super().__init__('Message "{}" not found.'.format(argument))
+
+class ChannelNotReadable(BadArgument):
+    """Exception raised when the bot does not have permission to read messages
+    in the channel.
+
+    This inherits from :exc:`BadArgument`
+
+    .. versionadded:: 1.5
+
+    Attributes
+    -----------
+    argument: :class:`Channel`
+        The channel supplied by the caller that was not readable
+    """
+    def __init__(self, argument):
+        self.argument = argument
+        super().__init__("Can't read messages in {}.".format(argument.mention))
+
+class ChannelNotFound(BadArgument):
+    """Exception raised when the bot can not find the channel.
+
+    This inherits from :exc:`BadArgument`
+
+    .. versionadded:: 1.5
+
+    Attributes
+    -----------
+    channel: :class:`str`
+        The channel supplied by the caller that was not found
+    """
+    def __init__(self, argument):
+        self.argument = argument
+        super().__init__('Channel "{}" not found.'.format(argument))
+
+class BadColourArgument(BadArgument):
+    """Exception raised when the colour is not valid.
+
+    This inherits from :exc:`BadArgument`
+
+    .. versionadded:: 1.5
+
+    Attributes
+    -----------
+    argument: :class:`str`
+        The colour supplied by the caller that was not valid
+    """
+    def __init__(self, argument):
+        self.argument = argument
+        super().__init__('Colour "{}" is invalid.'.format(argument))
+
+BadColorArgument = BadColourArgument
+
+class RoleNotFound(BadArgument):
+    """Exception raised when the bot can not find the role.
+
+    This inherits from :exc:`BadArgument`
+
+    .. versionadded:: 1.5
+
+    Attributes
+    -----------
+    argument: :class:`str`
+        The role supplied by the caller that was not found
+    """
+    def __init__(self, argument):
+        self.argument = argument
+        super().__init__('Role "{}" not found.'.format(argument))
+
+class BadInviteArgument(BadArgument):
+    """Exception raised when the invite is invalid or expired.
+
+    This inherits from :exc:`BadArgument`
+
+    .. versionadded:: 1.5
+    """
+    def __init__(self):
+        super().__init__('Invite is invalid or expired.')
+
+class EmojiNotFound(BadArgument):
+    """Exception raised when the bot can not find the emoji.
+
+    This inherits from :exc:`BadArgument`
+
+    .. versionadded:: 1.5
+
+    Attributes
+    -----------
+    argument: :class:`str`
+        The emoji supplied by the caller that was not found
+    """
+    def __init__(self, argument):
+        self.argument = argument
+        super().__init__('Emoji "{}" not found.'.format(argument))
+
+class PartialEmojiConversionFailure(BadArgument):
+    """Exception raised when the emoji provided does not match the correct
+    format.
+
+    This inherits from :exc:`BadArgument`
+
+    .. versionadded:: 1.5
+
+    Attributes
+    -----------
+    argument: :class:`str`
+        The emoji supplied by the caller that did not match the regex
+    """
+    def __init__(self, argument):
+        self.argument = argument
+        super().__init__('Couldn\'t convert "{}" to PartialEmoji.'.format(argument))
+
+class BadBooleanArgument(BadArgument):
+    """Exception raised when a boolean argument was not convertable.
+
+    This inherits from :exc:`BadArgument`
+
+    .. versionadded:: 1.5
+
+    Attributes
+    -----------
+    argument: :class:`str`
+        The boolean argument supplied by the caller that is not in the predefined list
+    """
+    def __init__(self, argument):
+        self.argument = argument
+        super().__init__('{} is not a recognised boolean option'.format(argument))
+
 class DisabledCommand(CommandError):
     """Exception raised when the command being invoked is disabled.
 

docs/ext/commands/api.rst

@@ -338,6 +338,39 @@ Exceptions
 .. autoexception:: discord.ext.commands.NotOwner
     :members:
 
+.. autoexception:: discord.ext.commands.MessageNotFound
+    :members:
+
+.. autoexception:: discord.ext.commands.MemberNotFound
+    :members:
+
+.. autoexception:: discord.ext.commands.UserNotFound
+    :members:
+
+.. autoexception:: discord.ext.commands.ChannelNotFound
+    :members:
+
+.. autoexception:: discord.ext.commands.ChannelNotReadable
+    :members:
+
+.. autoexception:: discord.ext.commands.InvalidColour
+    :members:
+
+.. autoexception:: discord.ext.commands.RoleNotFound
+    :members:
+
+.. autoexception:: discord.ext.commands.InvalidInvite
+    :members:
+
+.. autoexception:: discord.ext.commands.EmojiNotFound
+    :members:
+
+.. autoexception:: discord.ext.commands.PartialEmojiConversionFailure
+    :members:
+
+.. autoexception:: discord.ext.commands.BadBooleanArgument
+    :members:
+
 .. autoexception:: discord.ext.commands.MissingPermissions
     :members:
 
@@ -393,6 +426,17 @@ Exception Hierarchy
                 - :exc:`~.commands.MissingRequiredArgument`
                 - :exc:`~.commands.TooManyArguments`
                 - :exc:`~.commands.BadArgument`
+                    - :exc:`~.commands.MessageNotFound`
+                    - :exc:`~.commands.MemberNotFound`
+                    - :exc:`~.commands.UserNotFound`
+                    - :exc:`~.commands.ChannelNotFound`
+                    - :exc:`~.commands.ChannelNotReadable`
+                    - :exc:`~.commands.BadColourArgument`
+                    - :exc:`~.commands.RoleNotFound`
+                    - :exc:`~.commands.BadInviteArgument`
+                    - :exc:`~.commands.EmojiNotFound`
+                    - :exc:`~.commands.PartialEmojiConversionFailure`
+                    - :exc:`~.commands.BadBooleanArgument`
                 - :exc:`~.commands.BadUnionArgument`
                 - :exc:`~.commands.ArgumentParsingError`
                     - :exc:`~.commands.UnexpectedQuoteError`