1 files changed, 31 insertions, 0 deletions
diff --git a/app/services/resource_events/synthetic_milestone_notes_builder_service.rb b/app/services/resource_events/synthetic_milestone_notes_builder_service.rb
new file mode 100644
index 00000000000..ad58417834e
--- /dev/null
+++ b/app/services/resource_events/synthetic_milestone_notes_builder_service.rb
@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+# We store events about resource milestone changes in a separate table,
+# but we still want to display notes about milestone changes
+# as classic system notes in UI. This service generates "synthetic" notes for
+# milestone event changes.
+
+module ResourceEvents
+  class SyntheticMilestoneNotesBuilderService < BaseSyntheticNotesBuilderService
+    private
+
+    def synthetic_notes
+      return [] unless tracking_enabled?
+
+      milestone_change_events.map do |event|
+        MilestoneNote.from_event(event, resource: resource, resource_parent: resource_parent)
+      end
+    end
+
+    def milestone_change_events
+      return [] unless resource.respond_to?(:resource_milestone_events)
+
+      events = resource.resource_milestone_events.includes(user: :status) # rubocop: disable CodeReuse/ActiveRecord
+      since_fetch_at(events)
+    end
+
+    def tracking_enabled?
+      ::Feature.enabled?(:track_resource_milestone_change_events, resource.project)
+    end
+  end
+end