Add a/b test for feed style on new users (#20664)

* Add a/b test for feed style on new users

* Add current_user check

* Adjust to not look for current_user right away

* Move field test to the right place

app/controllers/application_controller.rb

@@ -221,8 +221,6 @@ class ApplicationController < ActionController::Base
   helper_method :internal_navigation?
 
   def feed_style_preference
-    # TODO: Future functionality will let current_user override this value with UX preferences
-    # if current_user exists and has a different preference.
     Settings::UserExperience.feed_style
   end
   helper_method :feed_style_preference

app/models/async_info.rb

@@ -5,6 +5,7 @@
 # @see UserDecorator
 # @see ApplicationPolicy
 class AsyncInfo
+  include FieldTest::Helpers
   # @api public
   #
   # Generate a Hash of the relevant user data.
@@ -46,7 +47,7 @@ class AsyncInfo
       trusted: user.trusted?,
       moderator_for_tags: user.moderator_for_tags,
       config_body_class: user.config_body_class,
-      feed_style: feed_style_preference,
+      feed_style: feed_style_preference_variable(user),
       created_at: user.created_at,
       admin: user.any_admin?,
       policies: [
@@ -75,4 +76,12 @@ class AsyncInfo
   rescue Pundit::NotAuthorizedError
     false
   end
+
+  def feed_style_preference_variable(user)
+    after_date = user.registered_at >= Time.zone.parse("2024-02-20")
+    flag_on = FeatureFlag.enabled?(:feed_style_test_running)
+    return field_test(:feed_style_20240220, participant: user) if after_date && flag_on
+
+    feed_style_preference
+  end
 end

config/field_test.yml

@@ -27,6 +27,27 @@
 ################################################################################
 ################################################################################
 experiments:
+  feed_style_20240220:
+    started_at: 2024-02-20
+    variants:
+      - basic
+      - rich
+    weights:
+      - 50
+      - 50
+    goals:
+      - user_creates_pageview
+      - user_creates_article_reaction
+      - user_creates_comment
+      - user_views_pages_on_at_least_two_different_days_within_a_week
+      - user_views_pages_on_at_least_four_different_days_within_a_week
+      - user_creates_article_reaction_on_four_different_days_within_a_week
+      - user_creates_comment_on_at_least_four_different_days_within_a_week
+      - user_views_pages_on_at_least_three_different_hours_within_a_day
+      - user_views_pages_on_at_least_four_different_hours_within_a_day
+      - user_views_pages_on_at_least_twelve_different_hours_within_five_days
+      - user_views_pages_on_at_least_nine_different_days_within_two_weeks
+
   comments_to_display_20240129:
     started_at: 2024-01-29
     variants: