Fix unlabeling using quick actions for epics

app/services/quick_actions/interpret_service.rb

@@ -210,8 +210,6 @@ module QuickActions
     end
     params '~label1 ~"label 2"'
     condition do
-      parent = project || issuable_group
-
       parent &&
         current_user.can?(:"admin_#{issuable.to_ability_name}", parent) &&
         find_labels.any?
@@ -241,7 +239,7 @@ module QuickActions
       issuable.is_a?(Issuable) &&
         issuable.persisted? &&
         issuable.labels.any? &&
-        current_user.can?(:"admin_#{issuable.to_ability_name}", project)
+        current_user.can?(:"admin_#{issuable.to_ability_name}", parent)
     end
     command :unlabel do |labels_param = nil|
       if labels_param.present?
@@ -670,6 +668,10 @@ module QuickActions
       MilestonesFinder.new(params.merge(project_ids: [project.id], group_ids: [project.group&.id])).execute
     end
 
+    def parent
+      project || issuable_group
+    end
+
     def issuable_group
       strong_memoize(:issuable_group) do
         issuable.group if issuable.respond_to?(:group)

ee/app/helpers/ee/application_helper.rb

@@ -74,7 +74,7 @@ module EE
       if object.is_a?(Group)
         {
           members: members_group_autocomplete_sources_path(object, type: noteable_type, type_id: params[:id]),
-          labels: labels_group_autocomplete_sources_path(object),
+          labels: labels_group_autocomplete_sources_path(object, type: noteable_type, type_id: params[:id]),
           epics: epics_group_autocomplete_sources_path(object),
           commands: commands_group_autocomplete_sources_path(object, type: noteable_type, type_id: params[:id]),
           milestones: milestones_group_autocomplete_sources_path(object)

ee/spec/services/ee/notes/quick_actions_service_spec.rb

@@ -197,5 +197,38 @@ describe Notes::QuickActionsService do
         end
       end
     end
+
+    describe '/label' do
+      let(:project) { nil }
+      let!(:bug) { create(:group_label, title: 'bug', group: group)}
+      let!(:feature) { create(:group_label, title: 'feature', group: group)}
+      let(:note_text) { "/unlabel ~bug" }
+      let(:note) { create(:note, noteable: epic, note: note_text) }
+
+      before do
+        group.add_developer(user)
+        epic.labels = [bug, feature]
+      end
+
+      context 'when epics are not enabled' do
+        it 'does not remove any label' do
+          expect { execute(note) }.not_to change { epic.reload.labels }
+        end
+      end
+
+      context 'when epics are enabled' do
+        before do
+          stub_licensed_features(epics: true)
+        end
+
+        it 'removes a requested label from the epic' do
+          expect { execute(note) }.to change { epic.reload.labels.map(&:title) }.to(['feature'])
+        end
+
+        it 'leaves the note empty' do
+          expect(execute(note)).to eq('')
+        end
+      end
+    end
   end
 end