Warm up the cache with the latest exercises daily

app/routines/warm_up_cache.rb

@@ -0,0 +1,17 @@
+class WarmUpCache
+  lev_routine transaction: :no_transaction
+
+  protected
+
+  def exec
+    Exercise.chainable_latest.find_in_batches(batch_size: 100) do |exercises|
+      Api::V1::Exercises::SearchRepresenter.new(items: exercises).to_hash(
+        user_options: { can_view_solutions: true }
+      )
+    end
+
+    VocabTerm.chainable_latest.find_in_batches(batch_size: 100) do |vocab_terms|
+      Api::V1::Vocabs::TermSearchRepresenter.new(items: vocab_terms).to_hash
+    end
+  end
+end

lib/tasks/cron/day.rake

@@ -5,6 +5,9 @@ namespace :cron do
     Rails.logger.info 'UpdateSlugs.call'
     OpenStax::RescueFrom.this { UpdateSlugs.call }
 
+    Rails.logger.info 'WarmUpCache.call'
+    OpenStax::RescueFrom.this { WarmUpCache.call }
+
     Rails.logger.debug 'Finished daily cron'
   end
 end

spec/lib/tasks/cron/day.rake_spec.rb

@@ -9,8 +9,9 @@
 
   before { Rake::Task['cron:day'].reenable }
 
-  it 'calls the UpdateSlugs lev routine' do
+  it 'calls the UpdateSlugs and WarmUpCache lev routines' do
     expect(UpdateSlugs).to receive(:call)
+    expect(WarmUpCache).to receive(:call)
 
     Rake.application.invoke_task 'cron:day'
   end

spec/routines/warm_up_cache_spec.rb

@@ -0,0 +1,22 @@
+require 'rails_helper'
+
+RSpec.describe WarmUpCache, type: :routine do
+  before do
+    5.times do
+      FactoryBot.create :exercise
+      FactoryBot.create :exercise, :published
+      FactoryBot.create :vocab_term, vocab_distractors_count: 1
+      FactoryBot.create :vocab_term, :published, vocab_distractors_count: 1
+    end
+  end
+
+  it 'caches all exercises and vocab terms' do
+    expect { described_class.call }.to(
+      change { Rails.cache.instance_variable_get(:@data).count }.by(60)
+    )
+
+    expect { described_class.call }.not_to(
+      change { Rails.cache.instance_variable_get(:@data).count }
+    )
+  end
+end