Add params filter to bulk update service

Filter params to allow epic value to be '0'
so that the attribute is removed.

ee/app/services/ee/issuable/bulk_update_service.rb

@@ -33,6 +33,41 @@ module EE
 
         params[:health_status] = nil if params[:health_status] == IssuableFinder::Params::NONE.to_s
       end
+
+      override :filter_update_params
+      def filter_update_params(type)
+        super
+        set_epic_param
+
+        params
+      end
+
+      def set_epic_param
+        return unless params[:epic].present?
+
+        epic_param = params.delete(:epic)
+        params[:epic] = nil if no_epic?(epic_param)
+        return if params[:epic].present?
+
+        epic = find_epic(epic_param)
+        params[:epic] = epic if epic.present?
+      end
+
+      # rubocop: disable CodeReuse/ActiveRecord
+      def find_epic(id)
+        group = parent.is_a?(Group) ? parent : parent.group
+        return unless group.present?
+
+        EpicsFinder.new(current_user, group_id: group.id,
+                        include_ancestor_groups: true).find(id)
+      rescue ActiveRecord::RecordNotFound
+        nil
+      end
+      # rubocop: enable CodeReuse/ActiveRecord
+
+      def no_epic?(epic_param)
+        epic_param == IssuableFinder::Params::NONE.to_s
+      end
     end
   end
 end

ee/app/services/ee/issues/update_service.rb

@@ -56,7 +56,7 @@ module EE
         epic_param = params.delete(:epic)
 
         if epic_param
-          EpicIssues::CreateService.new(::Epic.find(epic_param), current_user, { target_issuable: issue }).execute
+          EpicIssues::CreateService.new(epic_param, current_user, { target_issuable: issue }).execute
         else
           link = EpicIssue.find_by(issue_id: issue.id) # rubocop: disable CodeReuse/ActiveRecord
 

ee/spec/services/ee/issuable/bulk_update_service_spec.rb

@@ -34,6 +34,7 @@ RSpec.describe Issuable::BulkUpdateService do
     let(:issue1) { create(:issue, project: project1, health_status: :at_risk) }
     let(:issue2) { create(:issue, project: project2, health_status: :at_risk) }
     let(:issuables) { [issue1, issue2] }
+    let(:epic) { create(:epic, group: group) }
 
     before do
       group.add_reporter(user)
@@ -43,25 +44,28 @@ RSpec.describe Issuable::BulkUpdateService do
       let(:params) do
         {
           issuable_ids: issuables.map(&:id),
-          health_status: :on_track
+          health_status: :on_track,
+          epic_id: epic.id
         }
       end
 
       context 'when features are enabled' do
         before do
-          stub_licensed_features(issuable_health_status: true)
+          stub_licensed_features(issuable_health_status: true, epics: true)
         end
 
         it 'succeeds and returns the correct number of issuables updated' do
           expect(subject.success?).to be_truthy
           expect(subject.payload[:count]).to eq(issuables.count)
           issuables.each do |issuable|
-            expect(issuable.reload.health_status).to eq('on_track')
+            issuable.reload
+            expect(issuable.health_status).to eq('on_track')
+            expect(issuable.epic).to eq(epic)
           end
         end
 
         context "when params value is '0'" do
-          let(:params) { { issuable_ids: issuables.map(&:id), health_status: '0' } }
+          let(:params) { { issuable_ids: issuables.map(&:id), health_status: '0', epic_id: '0' } }
 
           it 'succeeds and remove values' do
             expect(subject.success?).to be_truthy
@@ -69,6 +73,7 @@ RSpec.describe Issuable::BulkUpdateService do
             issuables.each do |issuable|
               issuable.reload
               expect(issuable.health_status).to be_nil
+              expect(issuable.epic).to be_nil
             end
           end
         end
@@ -88,6 +93,14 @@ RSpec.describe Issuable::BulkUpdateService do
         end
 
         it_behaves_like 'does not update issuables attribute', :health_status
+        it_behaves_like 'does not update issuables attribute', :epic
+      end
+
+      context 'when user can not admin epic' do
+        let(:epic3) { create(:epic, group: create(:group)) }
+        let(:params) { { issuable_ids: issuables.map(&:id), epic: epic3.id } }
+
+        it_behaves_like 'does not update issuables attribute', :epic
       end
     end
   end