[V3] Send meaningful responses on conversion failure (#1817)

* [V3] Send meaningful responses on conversion failures

* Replace existing `discord.ext.commands` imports

Just to be sure

* Better Permissions converter response

redbot/cogs/admin/admin.py

@@ -1,9 +1,8 @@
 from typing import Tuple
 
 import discord
-from discord.ext import commands
 
-from redbot.core import Config, checks
+from redbot.core import Config, checks, commands
 
 import logging
 

redbot/cogs/admin/announcer.py

@@ -1,7 +1,7 @@
 import asyncio
 
 import discord
-from discord.ext import commands
+from redbot.core import commands
 
 
 class Announcer:

redbot/cogs/admin/converters.py

@@ -1,5 +1,5 @@
 import discord
-from discord.ext import commands
+from redbot.core import commands
 
 
 class MemberDefaultAuthor(commands.Converter):

redbot/cogs/alias/__init__.py

@@ -1,6 +1,6 @@
 from .alias import Alias
-from discord.ext import commands
+from redbot.core.bot import Red
 
 
-def setup(bot: commands.Bot):
+def setup(bot: Red):
     bot.add_cog(Alias(bot))

redbot/cogs/audio/__init__.py

@@ -5,7 +5,7 @@ import logging
 
 from .audio import Audio
 from .manager import start_lavalink_server
-from discord.ext import commands
+from redbot.core import commands
 from redbot.core.data_manager import cog_data_path
 import redbot.core
 

redbot/cogs/downloader/converters.py

@@ -1,6 +1,5 @@
 import discord
-from discord.ext import commands
-from .repo_manager import RepoManager
+from redbot.core import commands
 from .installable import Installable
 
 

redbot/cogs/downloader/repo_manager.py

@@ -2,17 +2,13 @@ import asyncio
 import functools
 import os
 import pkgutil
-import shutil
 from concurrent.futures import ThreadPoolExecutor
 from pathlib import Path
 from subprocess import run as sp_run, PIPE
 from sys import executable
 from typing import Tuple, MutableMapping, Union
 
-from discord.ext import commands
-
-from redbot.core import Config
-from redbot.core import data_manager
+from redbot.core import data_manager, commands
 from redbot.core.utils import safe_delete
 from .errors import *
 from .installable import Installable, InstallableType
@@ -232,7 +228,7 @@ class Repo(RepoJSONMixin):
         ----------
         branch : `str`, optional
             Override for repo's branch attribute.
-            
+
         Returns
         -------
         str
@@ -381,7 +377,7 @@ class Repo(RepoJSONMixin):
             Directory to install shared libraries to.
         libraries : `tuple` of `Installable`
             A subset of available libraries.
- 
+
         Returns
         -------
         bool
@@ -403,7 +399,7 @@ class Repo(RepoJSONMixin):
 
     async def install_requirements(self, cog: Installable, target_dir: Path) -> bool:
         """Install a cog's requirements.
-        
+
         Requirements will be installed via pip directly into
         :code:`target_dir`.
 
@@ -465,7 +461,7 @@ class Repo(RepoJSONMixin):
     @property
     def available_cogs(self) -> Tuple[Installable]:
         """`tuple` of `installable` : All available cogs in this Repo.
-        
+
         This excludes hidden or shared packages.
         """
         # noinspection PyTypeChecker

redbot/cogs/mod/checks.py

@@ -1,4 +1,4 @@
-from discord.ext import commands
+from redbot.core import commands
 import discord
 
 

redbot/cogs/permissions/converters.py

@@ -11,7 +11,10 @@ class CogOrCommand(commands.Converter):
         if ret:
             return "commands", ret.qualified_name
 
-        raise commands.BadArgument()
+        raise commands.BadArgument(
+            'Cog or command "{arg}" not found. Please note that this is case sensitive.'
+            "".format(arg=arg)
+        )
 
 
 class RuleType(commands.Converter):
@@ -21,4 +24,6 @@ class RuleType(commands.Converter):
         if arg.lower() in ("deny", "blacklist", "denied"):
             return "deny"
 
-        raise commands.BadArgument()
+        raise commands.BadArgument(
+            '"{arg}" is not a valid rule. Valid rules are "allow" or "deny"'.format(arg=arg)
+        )

redbot/cogs/trivia/trivia.py

@@ -2,7 +2,7 @@
 from collections import Counter
 import yaml
 import discord
-from discord.ext import commands
+from redbot.core import commands
 from redbot.ext import trivia as ext_trivia
 from redbot.core import Config, checks
 from redbot.core.data_manager import cog_data_path