Added new instrumentation support.

lib/jsonapi/serializer/instrumentation.rb

@@ -0,0 +1,27 @@
+require 'active_support/notifications'
+
+module JSONAPI
+  module Serializer
+    # Support for instrumentation
+    module Instrumentation
+      # Performance instrumentation namespace
+      NOTIFICATION_NAMESPACE = 'render.jsonapi-serializer.'.freeze
+
+      # Patch methods to use instrumentation...
+      %w[
+        serializable_hash
+        get_included_records
+        relationships_hash
+      ].each do |method_name|
+        define_method(method_name) do |*args|
+          ActiveSupport::Notifications.instrument(
+            NOTIFICATION_NAMESPACE + method_name,
+            { name: self.class.name, serializer: self.class }
+          ) do
+            super(*args)
+          end
+        end
+      end
+    end
+  end
+end

spec/fixtures/actor.rb

@@ -1,4 +1,5 @@
 require 'active_support/cache'
+require 'jsonapi/serializer/instrumentation'
 
 class Actor < User
   attr_accessor :movies, :movie_ids
@@ -70,3 +71,9 @@ module Cached
     )
   end
 end
+
+module Instrumented
+  class ActorSerializer < ::ActorSerializer
+    include ::JSONAPI::Serializer::Instrumentation
+  end
+end

spec/integration/instrumentation_spec.rb

@@ -0,0 +1,31 @@
+require 'spec_helper'
+
+# Needed to subscribe to `active_support/notifications`
+require 'concurrent'
+
+RSpec.describe JSONAPI::Serializer do
+  let(:serializer) do
+    Instrumented::ActorSerializer.new(Actor.fake)
+  end
+
+  it do
+    payload = event_name = nil
+    notification_name = (
+      ::JSONAPI::Serializer::Instrumentation::NOTIFICATION_NAMESPACE +
+        'serializable_hash'
+    )
+
+    ActiveSupport::Notifications.subscribe(
+      notification_name
+    ) do |ev_name, _s, _f, _i, ev_payload|
+      event_name = ev_name
+      payload = ev_payload
+    end
+
+    expect(serializer.serializable_hash).not_to be_nil
+
+    expect(event_name).to eq('render.jsonapi-serializer.serializable_hash')
+    expect(payload[:name]).to eq(serializer.class.name)
+    expect(payload[:serializer]).to eq(serializer.class)
+  end
+end