throw exception instance not class and add test

amqtt/plugins/logging.py

@@ -19,7 +19,7 @@ class EventLoggerPlugin:
     def __getattr__(self, name):
         if name.startswith("on_"):
             return partial(self.log_event, event_name=name)
-        raise AttributeError
+        raise AttributeError(f"'EventLoggerPlugin' object has no attribute {name!r}")
 
 
 class PacketLoggerPlugin:

tests/plugins/test_logging.py

@@ -0,0 +1,11 @@
+import pytest
+
+import amqtt.plugins.logging
+
+
+def test_EventLoggerPlugin_getattr():
+    logger = amqtt.plugins.logging.EventLoggerPlugin(None)
+    with pytest.raises(AttributeError) as exc:
+        logger.foo
+
+    assert "foo" in str(exc.value)