Remove exploding queries (#1018)

app/jobs/weekly_summary_email_job.rb

@@ -5,14 +5,28 @@ class WeeklySummaryEmailJob < ApplicationJob
     return unless Flipper.enabled?(:weekly_summary_emails)
 
     now_utc = reference_time.utc
-    cutoff = 3.weeks.ago
+    cutoff = now_utc - 3.weeks
 
-    User.subscribed("weekly_summary")
-        .where(created_at: cutoff..)
-        .or(User.subscribed("weekly_summary").joins(:heartbeats).where(heartbeats: { time: cutoff.. }))
-        .distinct
-        .find_each do |user|
+    eligible_users(cutoff).find_each do |user|
       WeeklySummaryUserEmailJob.perform_later(user.id, now_utc.iso8601)
     end
   end
+
+  private
+
+  def eligible_users(cutoff)
+    users = User.arel_table
+    heartbeats = Heartbeat.arel_table
+
+    recent_activity_exists = Heartbeat.unscoped
+      .where(heartbeats[:user_id].eq(users[:id]))
+      .where(heartbeats[:deleted_at].eq(nil))
+      .where(heartbeats[:time].gteq(cutoff.to_f))
+      .arel
+      .exists
+
+    User.subscribed("weekly_summary").where(
+      users[:created_at].gteq(cutoff).or(recent_activity_exists)
+    )
+  end
 end

test/jobs/weekly_summary_email_job_test.rb

@@ -5,6 +5,53 @@ class WeeklySummaryEmailJobTest < ActiveJob::TestCase
 
   setup do
     ActionMailer::Base.deliveries.clear
+    Flipper.enable(:weekly_summary_emails)
+    GoodJob::Job.delete_all
+  end
+
+  teardown do
+    Flipper.disable(:weekly_summary_emails)
+    GoodJob::Job.delete_all
+  end
+
+  test "enqueues for subscribed users who signed up recently or coded recently" do
+    reference_time = Time.utc(2026, 3, 1, 12, 0, 0)
+    cutoff = reference_time - 3.weeks
+
+    recent_signup = User.create!(timezone: "UTC")
+    recent_signup.update_column(:created_at, cutoff + 1.hour)
+
+    recent_coder = User.create!(timezone: "UTC")
+    recent_coder.update_column(:created_at, cutoff - 1.day)
+    create_coding_heartbeat(recent_coder, cutoff + 2.hours, "recent-coder", "Ruby")
+
+    stale_user = User.create!(timezone: "UTC")
+    stale_user.update_column(:created_at, cutoff - 1.day)
+    create_coding_heartbeat(stale_user, cutoff - 2.hours, "stale-user", "Ruby")
+
+    unsubscribed_recent_coder = User.create!(timezone: "UTC")
+    unsubscribed_recent_coder.unsubscribe("weekly_summary")
+    create_coding_heartbeat(unsubscribed_recent_coder, cutoff + 3.hours, "unsubscribed", "Ruby")
+
+    assert_difference -> { GoodJob::Job.where(job_class: "WeeklySummaryUserEmailJob").count }, 2 do
+      WeeklySummaryEmailJob.perform_now(reference_time)
+    end
+
+    jobs = GoodJob::Job.where(job_class: "WeeklySummaryUserEmailJob").order(:id)
+    enqueued_user_ids = jobs.map { |job| job.serialized_params.fetch("arguments").first.to_i }.sort
+    enqueued_reference_times = jobs.map { |job| job.serialized_params.fetch("arguments").second }.uniq
+
+    assert_equal [ recent_signup.id, recent_coder.id ].sort, enqueued_user_ids
+    assert_equal [ reference_time.iso8601 ], enqueued_reference_times
+  end
+
+  test "does not enqueue summaries when feature flag is disabled" do
+    Flipper.disable(:weekly_summary_emails)
+    User.create!(timezone: "UTC")
+
+    assert_no_difference -> { GoodJob::Job.where(job_class: "WeeklySummaryUserEmailJob").count } do
+      WeeklySummaryEmailJob.perform_now(Time.utc(2026, 3, 1, 12, 0, 0))
+    end
   end
 
   test "sends weekly summaries only for opted-in users with email at friday 17:30 utc" do