Correct error propagation for help command

dynamo/_typing.py

@@ -6,7 +6,7 @@
 P = ParamSpec("P")
 T = TypeVar("T")
 
-AsyncCallable = TypeVar("AC", bound=Callable[P, Coroutine[Any, Any, T]])
+AsyncCallable = TypeVar("AsyncCallable", bound=Callable[P, Coroutine[Any, Any, T]])
 CogT = TypeVar("CogT", bound=commands.Cog)
 CommandT = TypeVar("CommandT", bound=commands.Command[CogT, P, T])
 ContextT = TypeVar("ContextT", bound=commands.Context[Any], covariant=True)

dynamo/extensions/cogs/errors.py

@@ -1,4 +1,4 @@
-from typing import Any, Callable, Coroutine, Mapping
+from typing import Any, Callable, Coroutine
 
 import discord
 from discord import Interaction, app_commands
@@ -7,41 +7,21 @@
 
 from dynamo.core import Dynamo, DynamoCog
 from dynamo.utils.context import Context
+from dynamo.utils.error_types import NotFoundWithHelp, app_command_error_messages, command_error_messages
 
 
 class Errors(DynamoCog):
     """Handles errors for the bot."""
 
-    command_error_messages: Mapping[type[commands.CommandError], str] = {
-        commands.CommandNotFound: "Command not found: **`{}`**{}",
-        commands.MissingRequiredArgument: "Missing required argument: `{}`.",
-        commands.BadArgument: "Bad argument.",
-        commands.CommandOnCooldown: "You are on cooldown. Try again in `{:.2f}` seconds.",
-        commands.TooManyArguments: "Too many arguments.",
-        commands.MissingPermissions: "You are not allowed to use this command.",
-        commands.BotMissingPermissions: "I am not allowed to use this command.",
-        commands.NoPrivateMessage: "This command can only be used in a server.",
-        commands.NotOwner: "You are not the owner of this bot.",
-        commands.DisabledCommand: "This command is disabled.",
-        commands.CheckFailure: "You do not have permission to use this command.",
-    }
-
-    app_command_error_messages: Mapping[type[app_commands.AppCommandError], str] = {
-        app_commands.CommandNotFound: "Command not found: **`{}`**{}",
-        app_commands.CommandOnCooldown: "You are on cooldown. Try again in `{:.2f}` seconds.",
-        app_commands.MissingPermissions: "You are not allowed to use this command.",
-        app_commands.BotMissingPermissions: "I am not allowed to use this command.",
-        app_commands.NoPrivateMessage: "This command can only be used in a server.",
-        app_commands.CheckFailure: "You do not have permission to use this command.",
-    }
-
     def __init__(self, bot: Dynamo) -> None:
         super().__init__(bot)
 
         self.old_tree_error: Callable[
             [Interaction[Dynamo], app_commands.AppCommandError], Coroutine[Any, Any, None]
         ] = self.bot.tree.on_error
         self.bot.tree.on_error = self.on_app_command_error
+        self.command_error_messages = command_error_messages
+        self.app_command_error_messages = app_command_error_messages
 
     async def cog_unload(self) -> None:
         """Restores the old tree error handler on unload."""
@@ -93,14 +73,19 @@ async def on_command_error(self, ctx: Context, error: commands.CommandError) ->
 
         error_message = self.get_command_error_message(error)
 
-        if isinstance(error, commands.CommandNotFound):
+        if isinstance(error, (commands.CommandNotFound, NotFoundWithHelp)):
+            trigger = ctx.invoked_with if isinstance(error, commands.CommandNotFound) else error.args[0]
+
             matches = [
                 f"**{command.qualified_name}** - {command.short_doc or 'No description provided'}"
                 for command in self.bot.commands
-                if fuzz.partial_ratio(ctx.invoked_with, command.name) > 70
+                if fuzz.ratio(trigger, command.name) > 70
             ]
-            matches_string = f"\n\nDid you mean {f'\N{RIGHT-POINTING MAGNIFYING GLASS}\n>>> {'\n'.join(matches)}' if matches else ''}"
-            error_message = error_message.format(ctx.invoked_with, matches_string)
+            matches_string = (
+                f"\n\nDid you mean \N{RIGHT-POINTING MAGNIFYING GLASS}\n>>> {'\n'.join(matches)}" if matches else ""
+            )
+
+            error_message = error_message.format(trigger, matches_string)
 
         elif isinstance(error, commands.MissingRequiredArgument):
             error_message = error_message.format(error.param.name)
@@ -126,14 +111,12 @@ async def on_app_command_error(self, interaction: Interaction, error: app_comman
             self.log.error("Command not found: %s.", interaction.data)
             command_name = interaction.data.get("name", "")
             matches = [
-                command
-                for command in self.bot.tree.get_commands()
-                if fuzz.partial_ratio(command_name, command.name) > 70
+                command for command in self.bot.tree.get_commands() if fuzz.ratio(command_name, command.name) > 70
             ]
-            msg = (
-                f"Command not found: '{command_name}'"
-                f"\n\n{f'Did you mean \N{RIGHT-POINTING MAGNIFYING GLASS}\n>>> {'\n'.join(matches)}' if matches else ''}"
-            )
+            msg = f"Command not found: '{command_name}'"
+            if matches:
+                msg += f"\n\nDid you mean \N{RIGHT-POINTING MAGNIFYING GLASS}\n>>> {'\n'.join(matches)}"
+
             await interaction.response.send_message(
                 ephemeral=True,
                 content=msg,

dynamo/extensions/cogs/help.py

@@ -1,12 +1,13 @@
 import logging
 from dataclasses import dataclass
-from typing import Any, Mapping, TypedDict
+from typing import Any, Mapping, Never, TypedDict
 
 import discord
 from discord.ext import commands
 
 from dynamo._typing import CogT, CommandT
 from dynamo.core import Dynamo, DynamoCog
+from dynamo.utils.error_types import NotFoundWithHelp
 from dynamo.utils.format import code_block, human_join
 
 log = logging.getLogger(__name__)
@@ -49,15 +50,19 @@ async def send_bot_help(self, mapping: Mapping[CogT, list[CommandT]]) -> None:
         embed = HelpEmbed(title=f"{ctx.me.display_name} Help")
         embed.set_thumbnail(url=ctx.me.display_avatar)
 
-        for cog, commands in mapping.items():
-            filtered_commands = await self.filter_commands(commands)
+        for cog, command in mapping.items():
+            filtered_commands = await self.filter_commands(command)
             if (cog and cog.qualified_name not in self.blacklisted) and filtered_commands:
-                cog_field = await self.add_cog_commands_to_embed(cog, commands)
+                cog_field = await self.add_cog_commands_to_embed(cog, command)
                 if cog_field is not None:
                     embed.add_field(**cog_field)
 
         await self.send(embed=embed)
 
+    def command_not_found(self, string: str) -> Never:
+        log.debug("Command not found: %s", string)
+        raise NotFoundWithHelp(string)
+
     async def add_cog_commands_to_embed(self, cog: CogT, commands: list[CommandT]) -> EmbedField | None:
         name = cog.qualified_name if cog else "None"
         filtered_commands = await self.filter_commands(commands)

dynamo/utils/error_types.py

@@ -0,0 +1,32 @@
+from collections.abc import Mapping
+
+from discord import app_commands
+from discord.ext import commands
+
+
+class NotFoundWithHelp(commands.CommandError): ...
+
+
+command_error_messages: Mapping[type[commands.CommandError], str] = {
+    commands.CommandNotFound: "Command not found: **`{}`**{}",
+    NotFoundWithHelp: "Command not found: **`{}`**{}",
+    commands.MissingRequiredArgument: "Missing required argument: `{}`.",
+    commands.BadArgument: "Bad argument.",
+    commands.CommandOnCooldown: "You are on cooldown. Try again in `{:.2f}` seconds.",
+    commands.TooManyArguments: "Too many arguments.",
+    commands.MissingPermissions: "You are not allowed to use this command.",
+    commands.BotMissingPermissions: "I am not allowed to use this command.",
+    commands.NoPrivateMessage: "This command can only be used in a server.",
+    commands.NotOwner: "You are not the owner of this bot.",
+    commands.DisabledCommand: "This command is disabled.",
+    commands.CheckFailure: "You do not have permission to use this command.",
+}
+
+app_command_error_messages: Mapping[type[app_commands.AppCommandError], str] = {
+    app_commands.CommandNotFound: "Command not found: **`{}`**{}",
+    app_commands.CommandOnCooldown: "You are on cooldown. Try again in `{:.2f}` seconds.",
+    app_commands.MissingPermissions: "You are not allowed to use this command.",
+    app_commands.BotMissingPermissions: "I am not allowed to use this command.",
+    app_commands.NoPrivateMessage: "This command can only be used in a server.",
+    app_commands.CheckFailure: "You do not have permission to use this command.",
+}