Extract project's indexing association as method

ee/app/models/concerns/elastic/projects_search.rb

@@ -12,6 +12,14 @@ module Elastic
       repository_access_level
     ).freeze
 
+    INDEXED_ASSOCIATIONS = [
+      :issues,
+      :merge_requests,
+      :snippets,
+      :notes,
+      :milestones
+    ].freeze
+
     included do
       include ApplicationSearch
 
@@ -97,6 +105,26 @@ module Elastic
 
         self.__elasticsearch__.search(query_hash)
       end
+
+      def self.indexed_association_classes
+        INDEXED_ASSOCIATIONS.map do |association_name|
+          reflect_on_association(association_name).klass
+        end
+      end
+
+      def each_indexed_association
+        INDEXED_ASSOCIATIONS.each do |association_name|
+          association = self.association(association_name)
+          scope = association.scope
+          klass = association.klass
+
+          if klass == Note
+            scope = scope.searchable
+          end
+
+          yield klass, scope
+        end
+      end
     end
   end
 end

ee/app/workers/elastic_indexer_worker.rb

@@ -62,13 +62,7 @@ class ElasticIndexerWorker
   end
 
   def initial_index_project(project)
-    {
-      Issue        => project.issues,
-      MergeRequest => project.merge_requests,
-      Snippet      => project.snippets,
-      Note         => project.notes.searchable,
-      Milestone    => project.milestones
-    }.each do |klass, objects|
+    project.each_indexed_association do |klass, objects|
       objects.find_each { |object| import(:index, object, klass) }
     end