♻️ Push members down now that there is only one subclass

app/services/deprecation_warnings/production_handler.rb

@@ -1,15 +1,15 @@
 # frozen_string_literal: true
 
-require_relative "base_handler"
-
 # @note For use with `ActiveSupport::Deprecation.behavior=` or `Rails.application.config.active_support.deprecation=`
 module DeprecationWarnings
-  class ProductionHandler < BaseHandler
+  class ProductionHandler
     APP_NAME = "caseflow"
     SLACK_ALERT_TITLE = "Deprecation Warning - #{APP_NAME} (#{ENV['DEPLOY_ENV']})"
     SLACK_ALERT_CHANNEL = "#appeals-deprecation-alerts"
 
     class << self
+      # Adhere to `.call` signature expected by `ActiveSupport::Deprecation.behavior=`.
+      #   https://github.com/rails/rails/blob/a4581b53aae93a8dd3205abae0630398cbce9204/activesupport/lib/active_support/deprecation/behaviors.rb#L70-L71
       # :reek:LongParameterList
       def call(message, callstack, deprecation_horizon, gem_name)
         emit_warning_to_sentry(message, callstack, deprecation_horizon, gem_name)
@@ -18,6 +18,13 @@ def call(message, callstack, deprecation_horizon, gem_name)
         Raven.capture_exception(error)
       end
 
+      # Must respond to `.arity` to play nice with `ActiveSupport::Deprecation.behavior=`
+      #   and return number of arguments accepted by `.call`.
+      #   https://github.com/rails/rails/blob/a4581b53aae93a8dd3205abae0630398cbce9204/activesupport/lib/active_support/deprecation/behaviors.rb#L101
+      def arity
+        method(:call).arity
+      end
+
       private
 
       # :reek:LongParameterList