From 1a3abc22f8f4ce0b985e9db4c301009253460642 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ga=C3=ABlle=20Nicolas-Robardet?= <git@gaelle.pink>
Date: Wed, 2 Feb 2022 20:03:39 +0100
Subject: [PATCH] Add a reply on failed commands

---
 maubot/handlers/command.py | 24 +++++++++++++++++++++---
 1 file changed, 21 insertions(+), 3 deletions(-)

diff --git a/maubot/handlers/command.py b/maubot/handlers/command.py
index 37f8174..4789fd7 100644
--- a/maubot/handlers/command.py
+++ b/maubot/handlers/command.py
@@ -26,6 +26,15 @@ from mautrix.types import MessageType, EventType
 from ..matrix import MaubotMessageEvent
 from . import event
 
+
+class CommandError(Exception):
+    pass
+
+
+class CommandFailure(CommandError):
+    pass
+
+
 PrefixType = Optional[Union[str, Callable[[], str], Callable[[Any], str]]]
 AliasesType = Union[List[str], Tuple[str, ...], Set[str], Callable[[str], bool],
                     Callable[[Any, str], bool]]
@@ -116,9 +125,18 @@ class CommandHandler:
             await evt.reply(self.__mb_full_help__)
             return
 
-        if self.__bound_instance__:
-            return await self.__mb_func__(self.__bound_instance__, evt, **call_args)
-        return await self.__mb_func__(evt, **call_args)
+        try:
+            if self.__bound_instance__:
+                return await self.__mb_func__(self.__bound_instance__, evt, **call_args)
+            return await self.__mb_func__(evt, **call_args)
+        except CommandFailure as e:
+            await evt.reply(f"Error: {e}")
+        except CommandError as e:
+            await evt.reply(f"Error: {e}")
+            raise e
+        except Exception as e:
+            await evt.reply("An error happened while running the command")
+            raise e
 
     async def __call_subcommand__(self, evt: MaubotMessageEvent, call_args: Dict[str, Any],
                                   remaining_val: str) -> Tuple[bool, Any]: