Add Event driven Instrumentation (#1)

lib/recaptcha.rb

@@ -8,6 +8,7 @@
 require 'recaptcha/helpers'
 require 'recaptcha/adapters/controller_methods'
 require 'recaptcha/adapters/view_methods'
+require 'recaptcha/instrumentation'
 if defined?(Rails)
   require 'recaptcha/railtie'
 end
@@ -99,6 +100,9 @@ def self.verify_via_api_call_free(response, options)
     verify_hash['remoteip'] = options[:remote_ip] if options.key?(:remote_ip)
 
     reply = api_verification_free(verify_hash, timeout: options[:timeout], json: options[:json])
+    Instrumentation.report(
+      { token: response, options: options, response: reply }
+    )
     success = reply['success'].to_s == 'true' &&
       hostname_valid?(reply['hostname'], options[:hostname]) &&
       action_valid?(reply['action'], options[:action]) &&

lib/recaptcha/instrumentation.rb

@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+module Recaptcha
+  class Instrumentation
+    CHANNEL = 'Recaptcha::API::Response'
+
+    def self.report(payload = {})
+      ActiveSupport::Notifications.instrument(CHANNEL, payload)
+    end
+
+    def self.subscribe(&block)
+      ActiveSupport::Notifications.subscribe(CHANNEL) do |*args|
+        event = ActiveSupport::Notifications::Event.new(*args)
+
+        yield event if block_given?
+      end
+    end
+  end
+end