Merge pull request #30 from otobus/mustafaturan/update_logger_msg

Update log message for empty subscribers

lib/event_bus/services/notification.ex

@@ -13,7 +13,10 @@ defmodule EventBus.Service.Notification do
     listeners = Subscription.subscribers(topic)
 
     if listeners == [] do
-      Logger.log(@logging_level, "Topic :#{topic} listener set is empty!")
+      Logger.log(
+        @logging_level,
+        "Topic(:#{topic}#{registration_status(topic)}) doesn't have subscribers"
+      )
     else
       :ok = Store.create(event)
       :ok = Observation.create({listeners, topic, id})
@@ -45,6 +48,11 @@ defmodule EventBus.Service.Notification do
       Observation.mark_as_skipped({listener, topic, id})
   end
 
+  @spec registration_status(atom()) :: String.t()
+  defp registration_status(topic) do
+    if EventBus.topic_exist?(topic), do: "", else: " doesn't exist!"
+  end
+
   @spec log(module(), any()) :: no_return()
   defp log(listener, error) do
     msg = "#{listener}.process/1 raised an error!\n#{inspect(error)}"