Improve Error Message Readability in Lightning Protocol Tests

lnprototest/errors.py

@@ -20,7 +20,27 @@ def path_to_str(self) -> str:
             result += f"{event},"
         return f"{result}]"
 
+    @staticmethod
+    def decode_hex_data(hex_data: str) -> str:
+        """Decode hex data into readable text if possible"""
+        try:
+            # Try to decode as ASCII/UTF-8
+            decoded = bytes.fromhex(hex_data).decode("utf-8", errors="replace")
+            # If the decoded text is mostly readable, return it
+            if all(ord(c) < 128 for c in decoded):
+                return f" (decoded: {decoded})"
+        except (ValueError, UnicodeDecodeError):
+            pass
+        return ""
+
     def __str__(self) -> str:
+        # Look for hex data in the message and try to decode it
+        parts = self.message.split("data=")
+        if len(parts) > 1:
+            hex_data = parts[1].split()[0]  # Get the hex data before any spaces
+            decoded = self.decode_hex_data(hex_data)
+            if decoded:
+                self.message = self.message.replace(hex_data, f"{hex_data}{decoded}")
         return f"`{self.message}` on event {self.path_to_str()}"
 
 

lnprototest/event.py

@@ -374,8 +374,11 @@ def action(self, runner: "Runner") -> bool:
 
             err = self.message_match(runner, msg)
             if err:
-                raise EventError(self, "{}: message was {}".format(err, msg.to_str()))
-
+                # Format the error message to be more readable
+                error_msg = f"Expected {self.msgtype}, got {msg.messagetype.name}"
+                if hasattr(msg, "fields"):
+                    error_msg += f": {msg.to_str()}"
+                raise EventError(self, error_msg)
             break
         return True