Refactor callbacks in ams::logging

lib/active_model_serializers/logging.rb

@@ -1,31 +1,59 @@
 ##
 # Adapted from:
+#   https://github.com/rubygems/rubygems/blob/cb28f5e991/lib/rubygems/deprecate.rb
 #   https://github.com/rails/rails/blob/280654ef88/activejob/lib/active_job/logging.rb
+#
+# Provides a single method +notify+ to be used to declare when
+# something a method notifies.
+#
+#     class Adapter
+#       def self.klass_method
+#         # ...
+#       end
+#
+#       def instance_method
+#         # ...
+#       end
+#
+#       extend ActiveModelSerializers::Logging
+#       notify :instance_method, :render
+#
+#       class << self
+#         extend ActiveModelSerializers::Logging
+#         notify :klass_method, :render
+#       end
+#     end
 module ActiveModelSerializers::Logging
-  def self.included(base)
-    base.send(:include, ActiveSupport::Callbacks)
-    base.extend ClassMethods
-    base.class_eval do
-      define_callbacks :render
-      around_render do |_, block|
-        notify_active_support do
-          block.call
-        end
-      end
-    end
+  extend ActiveSupport::Concern
+
+  included do
+    include ActiveSupport::Callbacks
+    instrument_around_render
   end
 
   module ClassMethods
+    def instrument_around_render
+      define_callbacks :render
+      around_render do |args, block|
+        tag_logger do
+          notify_render do
+            block.call(args)
+          end
+        end
+      end
+    end
+
     def around_render(*filters, &blk)
       set_callback(:render, :around, *filters, &blk)
     end
+
     ##
     # Simple notify method that wraps up +name+
-    # in a dummy method. It notifies on each call to the dummy method
-    # telling what the current serializer and adapter are being rendered.
+    # in a dummy method. It notifies on with the +callback_name+ notifier on
+    # each call to the dummy method, telling what the current serializer and adapter
+    # are being rendered.
     # Adapted from:
     #   https://github.com/rubygems/rubygems/blob/cb28f5e991/lib/rubygems/deprecate.rb
-
     def notify(name, callback_name)
       class_eval do
         old = "_notifying_#{callback_name}_#{name}"
@@ -39,25 +67,39 @@ module ActiveModelSerializers::Logging
     end
   end
 
-  def notify_active_support
+  def notify_render(*)
     event_name = 'render.active_model_serializers'.freeze
-    payload = { serializer: serializer, adapter: adapter }
-    ActiveSupport::Notifications.instrument(event_name, payload) do
+    ActiveSupport::Notifications.instrument(event_name, notify_render_payload) do
       yield
     end
   end
 
+  def notify_render_payload
+    { serializer: serializer, adapter: adapter }
+  end
+
   private
 
+  def tag_logger(*tags)
+    if ActiveModelSerializers.logger.respond_to?(:tagged)
+      tags.unshift 'AMS'.freeze unless logger_tagged_by_active_model_serializers?
+      ActiveModelSerializers.logger.tagged(*tags) { yield }
+    else
+      yield
+    end
+  end
+
+  def logger_tagged_by_active_model_serializers?
+    ActiveModelSerializers.logger.formatter.current_tags.include?('AMS'.freeze)
+  end
+
   class LogSubscriber < ActiveSupport::LogSubscriber
     def render(event)
-      logger.tagged('AMS') do
-        info do
-          serializer = event.payload[:serializer]
-          adapter = event.payload[:adapter]
-          duration = event.duration.round(2)
-          "Rendered #{serializer.name} with #{adapter.class} (#{duration}ms)"
-        end
+      info do
+        serializer = event.payload[:serializer]
+        adapter = event.payload[:adapter]
+        duration = event.duration.round(2)
+        "Rendered #{serializer.name} with #{adapter.class} (#{duration}ms)"
       end
     end