Fix resource event when a label is removed

ee/app/models/ee/label_note.rb

@@ -18,7 +18,7 @@ module EE
     end
 
     def scoped_labels_event?
-      events.first.label.scoped_label?
+      events.first.label&.scoped_label?
     end
   end
 end

ee/spec/models/label_note_spec.rb

@@ -10,20 +10,28 @@ describe LabelNote do
   set(:label) { create(:group_label, group: group) }
   set(:label2) { create(:group_label, group: group) }
   let(:resource_parent) { group }
+  set(:resource) { create(:epic, group: group) }
+  let(:project) { nil }
+  let(:resource_key) { resource.class.name.underscore.to_s }
+  let(:events) { [create(:resource_label_event, label: label, resource_key => resource)] }
 
-  context 'when resource is epic' do
-    set(:resource) { create(:epic, group: group) }
-    let(:project) { nil }
+  subject { described_class.from_events(events) }
 
+  context 'when resource is epic' do
     it_behaves_like 'label note created from events'
 
     it 'includes a link to the list of epics filtered by the label' do
-      resource_key = resource.class.name.underscore.to_s
-      events = [build(:resource_label_event, label: label, resource_key => resource)]
+      expect(subject.note_html).to include(group_epics_path(group, label_name: label.title))
+    end
+  end
 
-      note = described_class.from_events(events)
+  context 'when a label is removed' do
+    it 'returns note correctly' do
+      events
+      label.destroy
+      events.first.reload
 
-      expect(note.note_html).to include(group_epics_path(group, label_name: label.title))
+      expect(subject.note).to include('deleted label')
     end
   end
 end