Refactor topic_checking to simplify booleans

amqtt/plugins/topic_checking.py

@@ -67,35 +67,35 @@ class TopicAccessControlListPlugin(BaseTopicPlugin):
 
     async def topic_filtering(self, *args, **kwargs):
         filter_result = super().topic_filtering(*args, **kwargs)
-        if filter_result:
-            session = kwargs.get("session", None)
-            req_topic = kwargs.get("topic", None)
-            action = kwargs.get("action", None)
+        if not filter_result:
+            return False
 
-            # hbmqtt and older amqtt do not support publish filtering
-            if action == Action.publish and "publish-acl" not in self.topic_config:
-                # maintain backward compatibility, assume permitted
+        # hbmqtt and older amqtt do not support publish filtering
+        action = kwargs.get("action", None)
+        if action == Action.publish and "publish-acl" not in self.topic_config:
+            # maintain backward compatibility, assume permitted
+            return True
+
+        req_topic = kwargs.get("topic", None)
+        if not req_topic:
+            return False
+
+        session = kwargs.get("session", None)
+        username = session.username
+        if username is None:
+            username = "anonymous"
+
+        if action == Action.publish:
+            acl = self.topic_config["publish-acl"]
+        elif action == Action.subscribe:
+            acl = self.topic_config["acl"]
+
+        allowed_topics = acl.get(username, None)
+        if not allowed_topics:
+            return False
+
+        for allowed_topic in allowed_topics:
+            if self.topic_ac(req_topic, allowed_topic):
                 return True
 
-            if req_topic:
-                username = session.username
-                if username is None:
-                    username = "anonymous"
-
-                if action == Action.publish:
-                    acl = self.topic_config["publish-acl"]
-                elif action == Action.subscribe:
-                    acl = self.topic_config["acl"]
-
-                allowed_topics = acl.get(username, None)
-                if allowed_topics:
-                    for allowed_topic in allowed_topics:
-                        if self.topic_ac(req_topic, allowed_topic):
-                            return True
-                    return False
-                else:
-                    return False
-            else:
-                return False
-        else:
-            return False
+        return False