Style guidelines applied

Author: ErvalhouS

CHANGELOG.asciidoc

@@ -22,6 +22,7 @@ endif::[]
 [float]
 ===== Changed
 - Change {pull}2526[#2526]
+- Racecar consumer instrumentation improvements {pull}
 
 [float]
 ===== Fixed

lib/elastic_apm/spies/racecar.rb

@@ -16,23 +16,24 @@
 # under the License.
 
 begin
-require 'active_support/notifications'
-require 'active_support/subscriber'
+  require 'active_support/notifications'
+  require 'active_support/subscriber'
 
   # frozen_string_literal: true
   module ElasticAPM
     # @api private
     module Spies
       # @api private
       class RacecarSpy
-        TYPE = 'kafka'
-        SUBTYPE = 'racecar'
+        TYPE = 'kafka'.freeze
+        SUBTYPE = 'racecar'.freeze
 
         # @api private
         class ConsumerSubscriber < ActiveSupport::Subscriber
           def start_process_message(event)
             start_process_transaction(event: event, kind: 'process_message')
           end
+
           def process_message(event)
             record_outcome(event: event)
             ElasticAPM.end_transaction
@@ -41,6 +42,7 @@ def process_message(event)
           def start_process_batch(event)
             start_process_transaction(event: event, kind: 'process_batch')
           end
+
           def process_batch(event)
             record_outcome(event: event)
             ElasticAPM.end_transaction
@@ -50,7 +52,8 @@ def process_batch(event)
 
           def start_process_transaction(event:, kind:)
             ElasticAPM.start_transaction("#{event.payload[:consumer_class]}##{kind}", TYPE)
-            ElasticAPM.current_transaction.context.set_service(framework_name: 'racecar', framework_version: Racecar::VERSION)
+            ElasticAPM.current_transaction.context.set_service(framework_name: 'racecar',
+              framework_version: Racecar::VERSION)
           end
 
           def record_outcome(event:)
@@ -61,10 +64,12 @@ def record_outcome(event:)
           end
         end
 
+        # @api private
         class ProducerSubscriber < ActiveSupport::Subscriber
-          def start_deliver_message(event)
-            ElasticAPM.start_transaction('deliver_message',TYPE)
-            ElasticAPM.current_transaction.context.set_service(framework_name: 'racecar', framework_version: Racecar::VERSION)
+          def start_deliver_message(_event)
+            ElasticAPM.start_transaction('deliver_message', TYPE)
+            ElasticAPM.current_transaction.context.set_service(framework_name: 'racecar',
+              framework_version: Racecar::VERSION)
           end
 
           def deliver_message(_event)
@@ -80,8 +85,7 @@ def install
       register 'Racecar', 'racecar', RacecarSpy.new
     end
   end
-
 rescue LoadError
   # no active support available
-  STDERR.puts "ActiveSupport not found."
+  warn "ActiveSupport not found."
 end

spec/elastic_apm/spies/racecar_spec.rb

@@ -24,16 +24,16 @@
   require 'racecar'
   module ElasticAPM
     RSpec.describe 'Spy: Racecar', :intercept do
-      let(:instrumentation_payload) {
+      let(:instrumentation_payload) do
         { consumer_class: 'SpecConsumer',
-          topic:          'spec_topic',
-          partition:      '0',
-          offset:         '1',
-          create_time:    Time.now,
-          key:            '1',
-          value:          {key: 'value'},
-          headers:        {key: 'value'} }
-      }
+          topic: 'spec_topic',
+          partition: '0',
+          offset: '1',
+          create_time: Time.now,
+          key: '1',
+          value: { key: 'value' },
+          headers: { key: 'value' } }
+      end
       it 'captures the instrumentation' do
         with_agent do
           ActiveSupport::Notifications.instrument('start_process_message.racecar', instrumentation_payload)
@@ -84,7 +84,6 @@ module ElasticAPM
       end
     end
   end
-
 rescue LoadError # in case we don't have ActiveSupport
-  STDERR.puts "ActiveSupport not found, skipping."
+  warn "ActiveSupport not found, skipping."
 end