1 files changed, 77 insertions, 1 deletions
diff --git a/bot/converters.py b/bot/converters.py
index 595809517..23aa9eab8 100644
--- a/bot/converters.py
+++ b/bot/converters.py
@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import logging
 import re
 import typing as t
@@ -11,13 +13,17 @@ import discord
 from aiohttp import ClientConnectorError
 from dateutil.relativedelta import relativedelta
 from discord.ext.commands import BadArgument, Bot, Context, Converter, IDConverter, UserConverter
-from discord.utils import DISCORD_EPOCH, snowflake_time
+from discord.utils import DISCORD_EPOCH, escape_markdown, snowflake_time
 
+from bot import exts
 from bot.api import ResponseCodeError
 from bot.constants import URLs
 from bot.exts.info.doc import _inventory_parser
+from bot.utils.extensions import EXTENSIONS, unqualify
 from bot.utils.regex import INVITE_RE
 from bot.utils.time import parse_duration_string
+if t.TYPE_CHECKING:
+    from bot.exts.info.source import SourceType
 
 log = logging.getLogger(__name__)
 
@@ -128,6 +134,44 @@ class ValidFilterListType(Converter):
         return list_type
 
 
+class Extension(Converter):
+    """
+    Fully qualify the name of an extension and ensure it exists.
+
+    The * and ** values bypass this when used with the reload command.
+    """
+
+    async def convert(self, ctx: Context, argument: str) -> str:
+        """Fully qualify the name of an extension and ensure it exists."""
+        # Special values to reload all extensions
+        if argument == "*" or argument == "**":
+            return argument
+
+        argument = argument.lower()
+
+        if argument in EXTENSIONS:
+            return argument
+        elif (qualified_arg := f"{exts.__name__}.{argument}") in EXTENSIONS:
+            return qualified_arg
+
+        matches = []
+        for ext in EXTENSIONS:
+            if argument == unqualify(ext):
+                matches.append(ext)
+
+        if len(matches) > 1:
+            matches.sort()
+            names = "\n".join(matches)
+            raise BadArgument(
+                f":x: `{argument}` is an ambiguous extension name. "
+                f"Please use one of the following fully-qualified names.```\n{names}```"
+            )
+        elif matches:
+            return matches[0]
+        else:
+            raise BadArgument(f":x: Could not find the extension `{argument}`.")
+
+
 class PackageName(Converter):
     """
     A converter that checks whether the given string is a valid package name.
@@ -290,6 +334,38 @@ class TagContentConverter(Converter):
         return tag_content
 
 
+class SourceConverter(Converter):
+    """Convert an argument into a help command, tag, command, or cog."""
+
+    @staticmethod
+    async def convert(ctx: Context, argument: str) -> SourceType:
+        """Convert argument into source object."""
+        if argument.lower() == "help":
+            return ctx.bot.help_command
+
+        cog = ctx.bot.get_cog(argument)
+        if cog:
+            return cog
+
+        cmd = ctx.bot.get_command(argument)
+        if cmd:
+            return cmd
+
+        tags_cog = ctx.bot.get_cog("Tags")
+        show_tag = True
+
+        if not tags_cog:
+            show_tag = False
+        elif argument.lower() in tags_cog._cache:
+            return argument.lower()
+
+        escaped_arg = escape_markdown(argument)
+
+        raise BadArgument(
+            f"Unable to convert '{escaped_arg}' to valid command{', tag,' if show_tag else ''} or Cog."
+        )
+
+
 class DurationDelta(Converter):
     """Convert duration strings into dateutil.relativedelta.relativedelta objects."""