fix: Simplified the error messages and added a bit more info to one of them

memphis/errors.py

@@ -0,0 +1,6 @@
+from dataclasses import dataclass
+
+@dataclass
+class Errors:
+    invalid_types = "The returned processed_message or processed_headers were not in the right format. processed_message must be bytes and processed_headers, dict"
+    conversion_error = "Returned message types from user function are not able to be converted into JSON:"

memphis/functions.py

@@ -1,6 +1,7 @@
 import json
 import base64
 import asyncio
+from errors import Errors
 
 def create_function(
     event,
@@ -105,12 +106,12 @@ async def handler(event):
                     })
                 elif processed_message is None and processed_headers is None: # filter out empty messages
                     continue
-                elif processed_message is None or processed_headers is None:
-                    err_msg = f"processed_messages is of type {type(processed_message)} and processed_headers is {type(processed_headers)}. Either both of these should be None or neither"
-                    raise Exception(err_msg)
                 else:
-                    err_msg = "The returned processed_message or processed_headers were not in the right format. processed_message must be bytes and processed_headers, dict"
-                    raise Exception(err_msg)
+                    err_msg = f"""Either processed_message or processed_headers were of the wrong type.
+processed_message should be of type bytes and processed_headers should be of type Dict. Ensure these types are correct.
+processed_message is of type {type(processed_message)} and processed_headers if of type {type(processed_headers)}.
+"""
+                    raise Exception(Errors.invalid_types)
             except Exception as e:
                 processed_events["failed_messages"].append({
                     "headers": message["headers"],
@@ -121,6 +122,6 @@ async def handler(event):
         try:
             return json.dumps(processed_events, cls=EncodeBase64).encode('utf-8')
         except Exception as e:
-            return f"Returned message types from user function are not able to be converted into JSON: {e}"
+            return f"Returned message types from user function are not able to be converted into JSON: {str(e)}"
 
     return asyncio.run(handler(event))