join room before sending message

matrix_webhook/handler.py

@@ -76,6 +76,11 @@ async def matrix_webhook(request):
     else:
         formatted_body = markdown(str(data["body"]), extensions=["extra"])
 
+    # try to join room first -> non none response means error
+    resp = await utils.join_room(data["room_id"])
+    if resp is not None:
+        return resp
+
     content = {
         "msgtype": "m.text",
         "body": data["body"],