1 files changed, 59 insertions, 10 deletions

diff --git a/lib/gitlab/experimentation.rb b/lib/gitlab/experimentation.rb
index 895755376ee..948f720b01b 100644
--- a/lib/gitlab/experimentation.rb
+++ b/lib/gitlab/experimentation.rb
@@ -14,13 +14,15 @@ module Gitlab
       signup_flow: {
         feature_toggle: :experimental_separate_sign_up_flow,
         environment: ::Gitlab.dev_env_or_com?,
-        enabled_ratio: 0.1
+        enabled_ratio: 0.1,
+        tracking_category: 'Growth::Acquisition::Experiment::SignUpFlow'
       }
     }.freeze
 
     # Controller concern that checks if an experimentation_subject_id cookie is present and sets it if absent.
     # Used for A/B testing of experimental features. Exposes the `experiment_enabled?(experiment_name)` method
-    # to controllers and views.
+    # to controllers and views. It returns true when the experiment is enabled and the user is selected as part
+    # of the experimental group.
     #
     module ControllerConcern
       extend ActiveSupport::Concern
@@ -36,22 +38,67 @@ module Gitlab
         cookies.permanent.signed[:experimentation_subject_id] = {
           value: SecureRandom.uuid,
           domain: :all,
-          secure: ::Gitlab.config.gitlab.https
+          secure: ::Gitlab.config.gitlab.https,
+          httponly: true
         }
       end
 
       def experiment_enabled?(experiment_key)
-        Experimentation.enabled?(experiment_key, experimentation_subject_index)
+        Experimentation.enabled_for_user?(experiment_key, experimentation_subject_index) || forced_enabled?(experiment_key)
+      end
+
+      def track_experiment_event(experiment_key, action)
+        track_experiment_event_for(experiment_key, action) do |tracking_data|
+          ::Gitlab::Tracking.event(tracking_data.delete(:category), tracking_data.delete(:action), tracking_data)
+        end
+      end
+
+      def frontend_experimentation_tracking_data(experiment_key, action)
+        track_experiment_event_for(experiment_key, action) do |tracking_data|
+          gon.push(tracking_data: tracking_data)
+        end
       end
 
       private
 
+      def experimentation_subject_id
+        cookies.signed[:experimentation_subject_id]
+      end
+
       def experimentation_subject_index
-        experimentation_subject_id = cookies.signed[:experimentation_subject_id]
         return if experimentation_subject_id.blank?
 
         experimentation_subject_id.delete('-').hex % 100
       end
+
+      def track_experiment_event_for(experiment_key, action)
+        return unless Experimentation.enabled?(experiment_key)
+
+        yield experimentation_tracking_data(experiment_key, action)
+      end
+
+      def experimentation_tracking_data(experiment_key, action)
+        {
+          category: tracking_category(experiment_key),
+          action: action,
+          property: tracking_group(experiment_key),
+          label: experimentation_subject_id
+        }
+      end
+
+      def tracking_category(experiment_key)
+        Experimentation.experiment(experiment_key).tracking_category
+      end
+
+      def tracking_group(experiment_key)
+        return unless Experimentation.enabled?(experiment_key)
+
+        experiment_enabled?(experiment_key) ? 'experimental_group' : 'control_group'
+      end
+
+      def forced_enabled?(experiment_key)
+        params.has_key?(:force_experiment) && params[:force_experiment] == experiment_key.to_s
+      end
     end
 
     class << self
@@ -59,18 +106,20 @@ module Gitlab
         Experiment.new(EXPERIMENTS[key].merge(key: key))
       end
 
-      def enabled?(experiment_key, experimentation_subject_index)
+      def enabled?(experiment_key)
         return false unless EXPERIMENTS.key?(experiment_key)
 
         experiment = experiment(experiment_key)
+        experiment.feature_toggle_enabled? && experiment.enabled_for_environment?
+      end
 
-        experiment.feature_toggle_enabled? &&
-          experiment.enabled_for_environment? &&
-          experiment.enabled_for_experimentation_subject?(experimentation_subject_index)
+      def enabled_for_user?(experiment_key, experimentation_subject_index)
+        enabled?(experiment_key) &&
+          experiment(experiment_key).enabled_for_experimentation_subject?(experimentation_subject_index)
       end
     end
 
-    Experiment = Struct.new(:key, :feature_toggle, :environment, :enabled_ratio, keyword_init: true) do
+    Experiment = Struct.new(:key, :feature_toggle, :environment, :enabled_ratio, :tracking_category, keyword_init: true) do
       def feature_toggle_enabled?
         return Feature.enabled?(key, default_enabled: true) if feature_toggle.nil?