Refactored: ActiveModelSerializers to use Datadog::Contrib::Integration.

lib/ddtrace.rb

@@ -44,7 +44,7 @@ def configure(target = configuration, opts = {})
 end
 
 require 'ddtrace/contrib/base'
-require 'ddtrace/contrib/active_model_serializers/patcher'
+require 'ddtrace/contrib/active_model_serializers/integration'
 require 'ddtrace/contrib/active_record/integration'
 require 'ddtrace/contrib/aws/integration'
 require 'ddtrace/contrib/concurrent_ruby/integration'

lib/ddtrace/contrib/active_model_serializers/configuration/settings.rb

@@ -0,0 +1,23 @@
+require 'ddtrace/contrib/configuration/settings'
+require 'ddtrace/contrib/active_model_serializers/ext'
+
+module Datadog
+  module Contrib
+    module ActiveModelSerializers
+      module Configuration
+        # Custom settings for the ActiveModelSerializers integration
+        class Settings < Contrib::Configuration::Settings
+          option :service_name, default: Ext::SERVICE_NAME
+          option :tracer, default: Datadog.tracer do |value|
+            (value || Datadog.tracer).tap do |v|
+              # Make sure to update tracers of all subscriptions
+              Events.subscriptions.each do |subscription|
+                subscription.tracer = v
+              end
+            end
+          end
+        end
+      end
+    end
+  end
+end

lib/ddtrace/contrib/active_model_serializers/event.rb

@@ -1,4 +1,6 @@
+require 'ddtrace/ext/http'
 require 'ddtrace/contrib/active_support/notifications/event'
+require 'ddtrace/contrib/active_model_serializers/ext'
 
 module Datadog
   module Contrib
@@ -31,12 +33,12 @@ def process(span, event, _id, payload)
             # Set the resource name and serializer name
             res = resource(payload[:serializer])
             span.resource = res
-            span.set_tag('active_model_serializers.serializer', res)
+            span.set_tag(Ext::TAG_SERIALIZER, res)
 
             span.span_type = Datadog::Ext::HTTP::TEMPLATE
 
             # Will be nil in 0.9
-            span.set_tag('active_model_serializers.adapter', payload[:adapter].class) unless payload[:adapter].nil?
+            span.set_tag(Ext::TAG_ADAPTER, payload[:adapter].class) unless payload[:adapter].nil?
           end
 
           private

lib/ddtrace/contrib/active_model_serializers/events/render.rb

@@ -1,3 +1,4 @@
+require 'ddtrace/contrib/active_model_serializers/ext'
 require 'ddtrace/contrib/active_model_serializers/event'
 
 module Datadog
@@ -9,7 +10,6 @@ module Render
           include ActiveModelSerializers::Event
 
           EVENT_NAME = 'render.active_model_serializers'.freeze
-          SPAN_NAME = 'active_model_serializers.render'.freeze
 
           module_function
 
@@ -23,7 +23,7 @@ def event_name
           end
 
           def span_name
-            self::SPAN_NAME
+            Ext::SPAN_RENDER
           end
         end
       end

lib/ddtrace/contrib/active_model_serializers/events/serialize.rb

@@ -1,3 +1,4 @@
+require 'ddtrace/contrib/active_model_serializers/ext'
 require 'ddtrace/contrib/active_model_serializers/event'
 
 module Datadog
@@ -9,7 +10,6 @@ module Serialize
           include ActiveModelSerializers::Event
 
           EVENT_NAME = '!serialize.active_model_serializers'.freeze
-          SPAN_NAME = 'active_model_serializers.serialize'.freeze
 
           module_function
 
@@ -26,7 +26,7 @@ def event_name
           end
 
           def span_name
-            self::SPAN_NAME
+            Ext::SPAN_SERIALIZE
           end
         end
       end

lib/ddtrace/contrib/active_model_serializers/ext.rb

@@ -0,0 +1,17 @@
+module Datadog
+  module Contrib
+    module ActiveModelSerializers
+      # ActiveModelSerializers integration constants
+      module Ext
+        APP = 'active_model_serializers'.freeze
+        SERVICE_NAME = 'active_model_serializers'.freeze
+
+        SPAN_RENDER = 'active_model_serializers.render'.freeze
+        SPAN_SERIALIZE = 'active_model_serializers.serialize'.freeze
+
+        TAG_ADAPTER = 'active_model_serializers.adapter'.freeze
+        TAG_SERIALIZER = 'active_model_serializers.serializer'.freeze
+      end
+    end
+  end
+end

lib/ddtrace/contrib/active_model_serializers/integration.rb

@@ -0,0 +1,39 @@
+require 'ddtrace/contrib/integration'
+require 'ddtrace/contrib/active_model_serializers/configuration/settings'
+require 'ddtrace/contrib/active_model_serializers/patcher'
+
+module Datadog
+  module Contrib
+    module ActiveModelSerializers
+      # Description of ActiveModelSerializers integration
+      class Integration
+        include Contrib::Integration
+
+        register_as :active_model_serializers
+
+        def self.version
+          Gem.loaded_specs['active_model_serializers'] \
+            && Gem.loaded_specs['active_model_serializers'].version
+        end
+
+        def self.present?
+          super && defined?(::ActiveModelSerializers)
+        end
+
+        def self.compatible?
+          super \
+            && defined?(::ActiveSupport::Notifications) \
+            && version >= Gem::Version.new('0.9.0')
+        end
+
+        def default_configuration
+          Configuration::Settings.new
+        end
+
+        def patcher
+          Patcher
+        end
+      end
+    end
+  end
+end

lib/ddtrace/contrib/active_model_serializers/patcher.rb

@@ -1,60 +1,41 @@
+require 'ddtrace/contrib/patcher'
 require 'ddtrace/ext/app_types'
-require 'ddtrace/ext/http'
+require 'ddtrace/contrib/active_model_serializers/ext'
 require 'ddtrace/contrib/active_model_serializers/events'
 
 module Datadog
   module Contrib
     module ActiveModelSerializers
-      # Provides instrumentation for ActiveModelSerializers through ActiveSupport instrumentation signals
+      # Patcher enables patching of 'active_model_serializers' module.
       module Patcher
-        include Base
+        include Contrib::Patcher
 
-        VERSION_REQUIRED = Gem::Version.new('0.9.0')
+        module_function
 
-        register_as :active_model_serializers
+        def patched?
+          done?(:active_model_serializers)
+        end
 
-        option :service_name, default: 'active_model_serializers'
-        option :tracer, default: Datadog.tracer do |value|
-          (value || Datadog.tracer).tap do |v|
-            # Make sure to update tracers of all subscriptions
-            Events.subscriptions.each do |subscription|
-              subscription.tracer = v
+        def patch
+          do_once(:active_model_serializers) do
+            begin
+              # Subscribe to ActiveModelSerializers events
+              Events.subscribe!
+
+              # Set service info
+              get_option(:tracer).set_service_info(
+                get_option(:service_name),
+                Ext::APP,
+                Datadog::Ext::AppTypes::WEB
+              )
+            rescue StandardError => e
+              Datadog::Tracer.log.error("Unable to apply ActiveModelSerializers integration: #{e}")
             end
           end
         end
 
-        class << self
-          def patch
-            return patched? if patched? || !compatible?
-
-            # Subscribe to ActiveModelSerializers events
-            Events.subscribe!
-
-            # Set service info
-            configuration[:tracer].set_service_info(
-              configuration[:service_name],
-              'active_model_serializers',
-              Ext::AppTypes::WEB
-            )
-
-            @patched = true
-          end
-
-          def patched?
-            return @patched if defined?(@patched)
-            @patched = false
-          end
-
-          private
-
-          def configuration
-            Datadog.configuration[:active_model_serializers]
-          end
-
-          def compatible?
-            Gem.loaded_specs['active_model_serializers'] && Gem.loaded_specs['activesupport'] \
-              && Gem.loaded_specs['active_model_serializers'].version >= VERSION_REQUIRED
-          end
+        def get_option(option)
+          Datadog.configuration[:active_model_serializers].get_option(option)
         end
       end
     end