Minor review improvements

* renamed scope
* added spec for disabled epics feature

ee/app/models/ee/epic.rb

@@ -95,7 +95,7 @@ module EE
       scope :due_date_inherited, -> { where(due_date_is_fixed: [nil, false]) }
 
       scope :counts_by_state, -> { group(:state_id).count }
-      scope :id_not_in, ->(ids) { where.not(id: ids) }
+      scope :excluding_ids, ->(ids) { where.not(id: ids) }
 
       MAX_HIERARCHY_DEPTH = 5
 

ee/app/services/epics/descendant_count_service.rb

@@ -31,7 +31,7 @@ module Epics
 
     def epics_count
       strong_memoize(:epics_count) do
-        accessible_epics.id_not_in([epic.id]).counts_by_state
+        accessible_epics.excluding_ids([epic.id]).counts_by_state
       end
     end
 

ee/spec/models/epic_spec.rb

@@ -117,11 +117,26 @@ describe Epic do
     context 'with authorized user' do
       before do
         private_group.add_developer(user)
-        stub_licensed_features(epics: true)
       end
 
-      it 'returns epic groups user can access' do
-        expect(subject).to eq [private_group]
+      context 'with epics enabled' do
+        before do
+          stub_licensed_features(epics: true)
+        end
+
+        it 'returns epic groups user can access' do
+          expect(subject).to eq [private_group]
+        end
+      end
+
+      context 'with epics are disabled' do
+        before do
+          stub_licensed_features(epics: false)
+        end
+
+        it 'returns an empty list' do
+          expect(subject).to be_empty
+        end
       end
     end
   end