Add coverage for `StatusTrend` and `PreviewCardTrend` models, add `locales` class method to `RankedTrend` (#32688)

app/controllers/admin/trends/links_controller.rb

@@ -4,7 +4,7 @@ class Admin::Trends::LinksController < Admin::BaseController
   def index
     authorize :preview_card, :review?
 
-    @locales       = PreviewCardTrend.pluck('distinct language')
+    @locales       = PreviewCardTrend.locales
     @preview_cards = filtered_preview_cards.page(params[:page])
     @form          = Trends::PreviewCardBatch.new
   end

app/controllers/admin/trends/statuses_controller.rb

@@ -4,7 +4,7 @@ class Admin::Trends::StatusesController < Admin::BaseController
   def index
     authorize [:admin, :status], :review?
 
-    @locales  = StatusTrend.pluck('distinct language')
+    @locales  = StatusTrend.locales
     @statuses = filtered_statuses.page(params[:page])
     @form     = Trends::StatusBatch.new
   end

app/models/concerns/ranked_trend.rb

@@ -9,6 +9,10 @@ module RankedTrend
   end
 
   class_methods do
+    def locales
+      distinct.pluck(:language)
+    end
+
     def recalculate_ordered_rank
       connection
         .exec_update(<<~SQL.squish)

app/models/trends/links.rb

@@ -85,7 +85,7 @@ class Trends::Links < Trends::Base
   end
 
   def request_review
-    PreviewCardTrend.pluck('distinct language').flat_map do |language|
+    PreviewCardTrend.locales.flat_map do |language|
       score_at_threshold  = PreviewCardTrend.where(language: language).allowed.by_rank.ranked_below(options[:review_threshold]).first&.score || 0
       preview_card_trends = PreviewCardTrend.where(language: language).not_allowed.joins(:preview_card)
 

app/models/trends/statuses.rb

@@ -78,7 +78,7 @@ class Trends::Statuses < Trends::Base
   end
 
   def request_review
-    StatusTrend.pluck('distinct language').flat_map do |language|
+    StatusTrend.locales.flat_map do |language|
       score_at_threshold = StatusTrend.where(language: language, allowed: true).by_rank.ranked_below(options[:review_threshold]).first&.score || 0
       status_trends      = StatusTrend.where(language: language, allowed: false).joins(:status).includes(status: :account)
 

spec/fabricators/preview_card_trend_fabricator.rb

@@ -0,0 +1,5 @@
+# frozen_string_literal: true
+
+Fabricator(:preview_card_trend) do
+  preview_card
+end

spec/fabricators/status_trend_fabricator.rb

@@ -0,0 +1,6 @@
+# frozen_string_literal: true
+
+Fabricator(:status_trend) do
+  status
+  account
+end

spec/models/preview_card_trend_spec.rb

@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe PreviewCardTrend do
+  describe 'Associations' do
+    it { is_expected.to belong_to(:preview_card).required }
+  end
+
+  describe '.locales' do
+    before do
+      Fabricate :preview_card_trend, language: 'en'
+      Fabricate :preview_card_trend, language: 'en'
+      Fabricate :preview_card_trend, language: 'es'
+    end
+
+    it 'returns unique set of languages' do
+      expect(described_class.locales)
+        .to eq(['en', 'es'])
+    end
+  end
+end

spec/models/status_trend_spec.rb

@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe StatusTrend do
+  describe 'Associations' do
+    it { is_expected.to belong_to(:account).required }
+    it { is_expected.to belong_to(:status).required }
+  end
+
+  describe '.locales' do
+    before do
+      Fabricate :status_trend, language: 'en'
+      Fabricate :status_trend, language: 'en'
+      Fabricate :status_trend, language: 'es'
+    end
+
+    it 'returns unique set of languages' do
+      expect(described_class.locales)
+        .to eq(['en', 'es'])
+    end
+  end
+end