DEV: Fix undefined method check_email_sync_heartbeat in unicorn conf (#30360)

This is a follow-up to 9812407f76

spec/lib/demon/email_sync_spec.rb

@@ -0,0 +1,53 @@
+# frozen_string_literal: true
+
+RSpec.describe Demon::EmailSync do
+  describe ".check_email_sync_heartbeat" do
+    after do
+      described_class.reset_demons
+      described_class.test_cleanup
+    end
+
+    it "should restart email sync daemons when last heartbeat is older than the heartbeat interval" do
+      track_log_messages do |logger|
+        daemon = described_class.new(1)
+        daemon.set_pid(999_999)
+
+        described_class.set_demons({ "daemon" => daemon })
+
+        Discourse.redis.set(
+          described_class::HEARTBEAT_KEY,
+          Time.now.to_i - described_class::HEARTBEAT_INTERVAL.to_i - 1,
+        )
+
+        daemon.expects(:restart)
+
+        described_class.check_email_sync_heartbeat
+
+        expect(logger.warnings.first).to eq(
+          "EmailSync heartbeat test failed (last heartbeat was 61s ago), restarting",
+        )
+      end
+    end
+
+    it "should restart email sync daemons when memory usage exceeds the maximum allowed memory" do
+      track_log_messages do |logger|
+        daemon = described_class.new(1)
+        daemon.set_pid(999_999)
+
+        described_class.set_demons({ "daemon" => daemon })
+
+        Discourse.redis.set(described_class::HEARTBEAT_KEY, Time.now.to_i)
+
+        daemon.expects(:restart)
+
+        # Set to negative value to fake that process is using too much memory
+        described_class.expects(:max_allowed_email_sync_rss).returns(-1)
+        described_class.check_email_sync_heartbeat
+
+        expect(logger.warnings.first).to eq(
+          "EmailSync is consuming too much memory (using: 0.00M) for '#{described_class::HOSTNAME}', restarting",
+        )
+      end
+    end
+  end
+end