Implement feedback fixes

app/controllers/registrations_controller.rb

@@ -16,7 +16,7 @@ class RegistrationsController < Devise::RegistrationsController
 
   def new
     if experiment_enabled?(:signup_flow)
-      track_experiment_event(:signup_flow, 'start')
+      track_experiment_event(:signup_flow, 'start') # We want this event to be tracked when the user is _in_ the experimental group
       @resource = build_resource
     else
       redirect_to new_user_session_path(anchor: 'register-pane')
@@ -24,7 +24,7 @@ def new
   end
 
   def create
-    track_experiment_event(:signup_flow, 'end') unless experiment_enabled?(:signup_flow)
+    track_experiment_event(:signup_flow, 'end') unless experiment_enabled?(:signup_flow) # We want this event to be tracked when the user is _in_ the control group
 
     accept_pending_invitations
 
@@ -64,7 +64,7 @@ def update_role
     result = ::Users::UpdateService.new(current_user, user_params.merge(user: current_user)).execute
 
     if result[:status] == :success
-      track_experiment_event(:signup_flow, 'end')
+      track_experiment_event(:signup_flow, 'end') # We want this event to be tracked when the user is _in_ the experimental group
       set_flash_message! :notice, :signed_up
       redirect_to stored_location_or_dashboard_or_almost_there_path(current_user)
     else

app/controllers/sessions_controller.rb

@@ -296,6 +296,7 @@ def authentication_method
   end
 
   def frontend_tracking_data
+    # We want tracking data pushed to the frontend when the user is _in_ the control group
     frontend_experimentation_tracking_data(:signup_flow, 'start') unless experiment_enabled?(:signup_flow)
   end
 end

lib/gitlab/experimentation.rb

@@ -47,17 +47,15 @@ def experiment_enabled?(experiment_key)
       end
 
       def track_experiment_event(experiment_key, action)
-        return unless Experimentation.enabled?(experiment_key)
-
-        tracking_data = experimentation_tracking_data(experiment_key, action)
-        ::Gitlab::Tracking.event(tracking_data.delete(:category), tracking_data.delete(:action), tracking_data)
+        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)
-        return unless Experimentation.enabled?(experiment_key)
-
-        tracking_data = experimentation_tracking_data(experiment_key, action)
-        gon.push(tracking_data: tracking_data)
+        track_experiment_event_for(experiment_key, action) do |tracking_data|
+          gon.push(tracking_data: tracking_data)
+        end
       end
 
       private
@@ -72,6 +70,12 @@ def experimentation_subject_index
         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),