refactor(kafka_consumer): apply review suggestions

lib-ee/emqx_ee_bridge/src/emqx_ee_bridge_kafka.erl

@@ -274,7 +274,9 @@ fields(consumer_kafka_opts) ->
             })},
         {max_rejoin_attempts,
             mk(non_neg_integer(), #{
-                default => 5, desc => ?DESC(consumer_max_rejoin_attempts)
+                hidden => true,
+                default => 5,
+                desc => ?DESC(consumer_max_rejoin_attempts)
             })},
         {offset_reset_policy,
             mk(

lib-ee/emqx_ee_bridge/src/kafka/emqx_bridge_impl_kafka_consumer.erl

@@ -129,7 +129,7 @@ on_start(InstanceId, Config) ->
             }),
             throw(failed_to_start_kafka_client)
     end,
-    start_subscriber(Config, InstanceId, ClientID).
+    start_consumer(Config, InstanceId, ClientID).
 
 -spec on_stop(manager_id(), state()) -> ok.
 on_stop(_InstanceID, State) ->
@@ -169,7 +169,10 @@ handle_message(Message, State) ->
     ?tp_span(
         kafka_consumer_handle_message,
         #{message => Message, state => State},
-        begin
+        do_handle_message(Message, State)
+    ).
+
+do_handle_message(Message, State) ->
     #{
         resource_id := ResourceId,
         hookpoint := Hookpoint,
@@ -203,9 +206,7 @@ handle_message(Message, State) ->
     emqx_resource_metrics:received_inc(ResourceId),
     %% note: just `ack' does not commit the offset to the
     %% kafka consumer group.
-            {ok, commit, State}
-        end
-    ).
+    {ok, commit, State}.
 
 %%-------------------------------------------------------------------------------------
 %% Helper fns
@@ -241,8 +242,8 @@ ensure_consumer_supervisor_started() ->
             ok
     end.
 
--spec start_subscriber(config(), manager_id(), brod:client_id()) -> {ok, state()}.
-start_subscriber(Config, InstanceId, ClientID) ->
+-spec start_consumer(config(), manager_id(), brod:client_id()) -> {ok, state()}.
+start_consumer(Config, InstanceId, ClientID) ->
     #{
         bootstrap_hosts := BootstrapHosts0,
         bridge_name := BridgeName,
@@ -256,7 +257,7 @@ start_subscriber(Config, InstanceId, ClientID) ->
         },
         mqtt := #{topic := MQTTTopic, qos := MQTTQoS, payload := MQTTPayload}
     } = Config,
-    ensure_consumer_supervisor_started(),
+    ok = ensure_consumer_supervisor_started(),
     InitialState = #{
         resource_id => emqx_bridge_resource:resource_id(kafka_consumer, BridgeName),
         mqtt => #{