Refactor SchoolConsentRemindersJob

This splits the job in to two separate jobs, one which runs on a
schedule and for each session queues up a separate job which handles the
process of sending the communications for a particular session.

We're finding that the current job is unable to handle a high number of
sessions and runs out of resources. Instead, by queuing a job for each
session we can avoid the individual jobs being too resource hungry and
gives us more flexibility in terms of running the jobs manually.

Author: thomasleese

app/jobs/enqueue_school_consent_reminders_job.rb

@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+class EnqueueSchoolConsentRemindersJob < ApplicationJob
+  queue_as :notifications
+
+  def perform
+    sessions =
+      Session.send_consent_reminders.joins(:location).merge(Location.school)
+
+    sessions.find_each do |session|
+      SendSchoolConsentRemindersJob.perform_later(session)
+    end
+  end
+end

app/jobs/school_consent_reminders_job.rb renamed to app/jobs/send_school_consent_reminders_job.rb

@@ -1,44 +1,35 @@
 # frozen_string_literal: true
 
-class SchoolConsentRemindersJob < ApplicationJob
+class SendSchoolConsentRemindersJob < ApplicationJob
   queue_as :notifications
 
-  def perform
-    sessions =
-      Session
-        .send_consent_reminders
-        .joins(:location)
-        .includes(:session_dates, :programmes, :patient_sessions, :location)
-        .merge(Location.school)
-
-    sessions.find_each(batch_size: 1) do |session|
-      next unless session.open_for_consent?
-
-      session.patient_sessions.each do |patient_session|
-        ProgrammeGrouper
-          .call(patient_session.programmes)
-          .each_value do |programmes|
-            next unless should_send_notification?(patient_session:, programmes:)
-
-            patient = patient_session.patient
-
-            sent_initial_reminder =
-              programmes.all? do |programme|
-                patient
-                  .consent_notifications
-                  .select { it.programmes.include?(programme) }
-                  .any?(&:initial_reminder?)
-              end
-
-            ConsentNotification.create_and_send!(
-              patient:,
-              programmes:,
-              session:,
-              type:
-                sent_initial_reminder ? :subsequent_reminder : :initial_reminder
-            )
-          end
-      end
+  def perform(session)
+    return unless session.school? && session.open_for_consent?
+
+    session.patient_sessions.includes_programmes.find_each do |patient_session|
+      ProgrammeGrouper
+        .call(patient_session.programmes)
+        .each_value do |programmes|
+          next unless should_send_notification?(patient_session:, programmes:)
+
+          patient = patient_session.patient
+
+          sent_initial_reminder =
+            programmes.all? do |programme|
+              patient
+                .consent_notifications
+                .select { it.programmes.include?(programme) }
+                .any?(&:initial_reminder?)
+            end
+
+          ConsentNotification.create_and_send!(
+            patient:,
+            programmes:,
+            session:,
+            type:
+              sent_initial_reminder ? :subsequent_reminder : :initial_reminder
+          )
+        end
     end
   end
 

config/environments/production.rb

@@ -108,9 +108,9 @@
       description:
         "Send school consent request emails to parents for each session"
     },
-    consent_reminder: {
+    school_consent_reminders: {
       cron: "every day at 9am",
-      class: "SchoolConsentRemindersJob",
+      class: "EnqueueSchoolConsentRemindersJob",
       description:
         "Send school consent reminder emails to parents for each session"
     },

spec/jobs/enqueue_school_consent_reminders_job_spec.rb

@@ -0,0 +1,75 @@
+# frozen_string_literal: true
+
+describe EnqueueSchoolConsentRemindersJob do
+  subject(:perform_now) { described_class.perform_now }
+
+  let(:programmes) { [create(:programme)] }
+  let(:organisation) { create(:organisation, programmes:) }
+  let(:location) { create(:school, organisation:) }
+
+  let(:dates) { [Date.new(2024, 1, 12), Date.new(2024, 1, 15)] }
+
+  let!(:session) do
+    create(
+      :session,
+      dates:,
+      send_consent_requests_at: dates.first - 3.weeks,
+      days_before_consent_reminders: 7,
+      location:,
+      programmes:,
+      organisation:
+    )
+  end
+
+  around { |example| travel_to(today) { example.run } }
+
+  context "two weeks before the first session" do
+    let(:today) { dates.first - 2.weeks }
+
+    it "doesn't queue any jobs" do
+      expect { perform_now }.not_to have_enqueued_job(
+        SendSchoolConsentRemindersJob
+      )
+    end
+  end
+
+  context "one week before the first session" do
+    let(:today) { dates.first - 1.week }
+
+    it "queues a job for the session" do
+      expect { perform_now }.to have_enqueued_job(
+        SendSchoolConsentRemindersJob
+      ).with(session)
+    end
+
+    context "when location is a generic clinic" do
+      let(:location) { create(:generic_clinic, organisation:) }
+
+      it "doesn't queue any jobs" do
+        expect { perform_now }.not_to have_enqueued_job(
+          SendSchoolConsentRemindersJob
+        )
+      end
+    end
+  end
+
+  context "one week before the second session" do
+    let(:today) { dates.last - 1.week }
+
+    it "queues a job for the session" do
+      expect { perform_now }.to have_enqueued_job(
+        SendSchoolConsentRemindersJob
+      ).with(session)
+    end
+
+    context "when location is a generic clinic" do
+      let(:location) { create(:generic_clinic, organisation:) }
+
+      it "doesn't queue any jobs" do
+        expect { perform_now }.not_to have_enqueued_job(
+          SendSchoolConsentRemindersJob
+        )
+      end
+    end
+  end
+end

spec/jobs/school_consent_reminders_job_spec.rb renamed to spec/jobs/send_school_consent_reminders_job_spec.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
-describe SchoolConsentRemindersJob do
-  subject(:perform_now) { described_class.perform_now }
+describe SendSchoolConsentRemindersJob do
+  subject(:perform_now) { described_class.perform_now(session) }
 
   let(:programmes) { [create(:programme)] }