Add spec for heartbeat job

Author: rossta

spec/jobs/emails/heartbeat_job_spec.rb

@@ -0,0 +1,19 @@
+require "rails_helper"
+
+RSpec.describe Emails::HeartbeatJob do
+  describe "#perform" do
+    it "sends a heartbeat email to admin users to exercise email provider integration" do
+      admin_user = FactoryBot.create(:admin_user)
+
+      Emails::HeartbeatJob.perform_later
+
+      perform_enqueued_jobs_and_subsequently_enqueued_jobs
+
+      expect(ActionMailer::Base.deliveries.count).to eq(1)
+
+      mail = find_mail_to(admin_user.email)
+
+      expect(mail.subject).to eq("It’s alive!")
+    end
+  end
+end