Add a/b test for which comments to show in feed (#20332)

* Add a/b test for which comments to show in feed

* Adjust figure

* Started at

* Move scope placement around

* Add tests for different comments_variants passed

* Fix typo

app/controllers/stories/feeds_controller.rb

@@ -4,6 +4,8 @@ module Stories
 
     def show
       @page = (params[:page] || 1).to_i
+      @comments_variant = field_test(:comments_to_display_20240129, participant: @user)
+
       @stories = assign_feed_stories
 
       add_pinned_article
@@ -55,7 +57,8 @@ module Stories
         # weighted strategy has not.  I also don't want to alter the
         # weighted query implementation as it returns a lovely
         # ActiveRecord::Relation.  So this is a compromise.
-        feed.more_comments_minimal_weight_randomized.to_a
+
+        feed.more_comments_minimal_weight_randomized(comments_variant: @comments_variant)
       end
     end
 

app/models/article.rb

@@ -146,6 +146,42 @@ class Article < ApplicationRecord
            inverse_of: :commentable,
            class_name: "Comment"
 
+  has_many :more_inclusive_top_comments,
+           lambda {
+             where(comments: { score: 5.. }, ancestry: nil, hidden_by_commentable_user: false, deleted: false)
+               .order("comments.score" => :desc)
+           },
+           as: :commentable,
+           inverse_of: :commentable,
+           class_name: "Comment"
+
+  has_many :recent_good_comments,
+           lambda {
+             where(comments: { score: 8.. }, ancestry: nil, hidden_by_commentable_user: false, deleted: false)
+               .order("comments.created_at" => :desc)
+           },
+           as: :commentable,
+           inverse_of: :commentable,
+           class_name: "Comment"
+
+  has_many :more_inclusive_recent_good_comments,
+           lambda {
+             where(comments: { score: 5.. }, ancestry: nil, hidden_by_commentable_user: false, deleted: false)
+               .order("comments.created_at" => :desc)
+           },
+           as: :commentable,
+           inverse_of: :commentable,
+           class_name: "Comment"
+
+  has_many :most_inclusive_recent_good_comments,
+           lambda {
+             where(comments: { score: 3.. }, ancestry: nil, hidden_by_commentable_user: false, deleted: false)
+               .order("comments.created_at" => :desc)
+           },
+           as: :commentable,
+           inverse_of: :commentable,
+           class_name: "Comment"
+
   validates :body_markdown, bytesize: {
     maximum: 800.kilobytes,
     too_long: proc { I18n.t("models.article.is_too_long") }

app/services/articles/feeds/variant_query.rb

@@ -90,7 +90,7 @@ module Articles
       #    puts strategy.call.to_sql
       #
       # rubocop:disable Layout/LineLength
-      def call(only_featured: false, must_have_main_image: false, limit: default_limit, offset: default_offset, omit_article_ids: [])
+      def call(only_featured: false, must_have_main_image: false, limit: default_limit, offset: default_offset, omit_article_ids: [], comments_variant: default_comments_variant)
         # rubocop:enable Layout/LineLength
 
         # These are the variables we'll pass to the SQL statement.
@@ -136,10 +136,24 @@ module Articles
         # goodness of scopes (e.g., limited_column_select) and eager includes.
         scope = Article.joins(join_fragment)
           .limited_column_select
-          .includes(top_comments: :user)
           .includes(:distinct_reaction_categories)
           .order(config.order_by.to_sql)
 
+        scope = case comments_variant
+                when "top_comments"
+                  scope.includes(top_comments: :user)
+                when "more_inclusive_top_comments"
+                  scope.includes(more_inclusive_top_comments: :user)
+                when "recent_good_comments"
+                  scope.includes(recent_good_comments: :user)
+                when "more_inclusive_recent_good_comments"
+                  scope.includes(more_inclusive_recent_good_comments: :user)
+                when "most_inclusive_recent_good_comments"
+                  scope.includes(most_inclusive_recent_good_comments: :user)
+                else
+                  scope.includes(top_comments: :user) # fallback default
+                end
+
         if @user.present? && (hidden_tags = @user.cached_antifollowed_tag_names).any?
           scope = scope.not_cached_tagged_with_any(hidden_tags)
         end
@@ -306,6 +320,10 @@ module Articles
         (@page.to_i - 1) * default_limit
       end
 
+      def default_comments_variant
+        "top_comments"
+      end
+
       # We want to ensure that we're not randomizing someone's feed all the time; and instead aiming
       # for somewhat repeatable experiences (e.g. I refresh the page it is likely I will have the
       # same order of pages even though we've randomized things a bit).

app/views/stories/feeds/show.json.jbuilder

@@ -29,7 +29,7 @@ json.array!(@stories) do |article|
   json.tag_list article.cached_tag_list_array
   json.extract! article, *article_methods_to_include
 
-  json.top_comments article.top_comments do |comment|
+  json.top_comments article.public_send(@comments_variant.to_sym) do |comment|
     comment = comment.decorate
     json.comment_id comment.id
     json.extract! comment, :user_id, :published_timestamp, :published_at_int, :safe_processed_html, :path

config/field_test.yml

@@ -27,6 +27,33 @@
 ################################################################################
 ################################################################################
 experiments:
+  comments_to_display_20240129:
+    started_at: 2024-01-29
+    variants:
+      - top_comments
+      - more_inclusive_top_comments
+      - recent_good_comments
+      - more_inclusive_recent_good_comments
+      - most_inclusive_recent_good_comments
+    weights:
+      - 60
+      - 10
+      - 10
+      - 10
+      - 10
+    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
+
   # NOTE: Our feed strategy testing experiment must begin with "feed_strategy"
   feed_strategy_starting_20240126:
     started_at: 2024-01-26

spec/services/articles/feeds/variant_query_spec.rb

@@ -58,6 +58,19 @@ RSpec.describe Articles::Feeds::VariantQuery, type: :service do
           expect(query_call).to be_a(ActiveRecord::Relation)
           expect(query_call.to_a).not_to include(article)
         end
+
+        it "returns proper scope when passed the different test values" do
+          # rubocop:disable Performance/CollectionLiteralInLoop
+          %w[top_comments
+             more_inclusive_top_comments
+             recent_good_comments
+             more_inclusive_recent_good_comments
+             most_inclusive_recent_good_comments].each do |test_value|
+            expect(variant_query.call(comments_variant: test_value).includes_values)
+              .to include(:distinct_reaction_categories, { test_value.to_sym => :user })
+          end
+          # rubocop:enable Performance/CollectionLiteralInLoop
+        end
       end
 
       describe "#featured_story_and_default_home_feed" do