Fixed error with GFM autocomplete when no data exists

app/assets/javascripts/gfm_auto_complete.js.es6

@@ -367,7 +367,7 @@
       return $input.trigger('keyup');
     },
     isLoading(data) {
-      if (!data) return false;
+      if (!data || !data.length) return false;
       if (Array.isArray(data)) data = data[0];
       return data === this.defaultLoadingData[0] || data.name === this.defaultLoadingData[0];
     },

changelogs/unreleased/label-gfm-error-fix.yml

+---
+title: Fixed GFM autocomplete error when no data exists
+merge_request:
+author:

spec/features/issues/gfm_autocomplete_spec.rb

@@ -47,7 +47,7 @@ feature 'GFM autocomplete', feature: true, js: true do
       expect_to_wrap(true, label_item, note, label.title)
     end
 
-    it "does not show drpdown when preceded with a special character" do
+    it "does not show dropdown when preceded with a special character" do
       note = find('#note_note')
       page.within '.timeline-content-form' do
         note.native.send_keys('')
@@ -65,6 +65,17 @@ feature 'GFM autocomplete', feature: true, js: true do
       expect(page).to have_selector('.atwho-container', visible: false)
     end
 
+    it "does not throw an error if no labels exist" do
+      note = find('#note_note')
+      page.within '.timeline-content-form' do
+        note.native.send_keys('')
+        note.native.send_keys('~')
+        note.click
+      end
+
+      expect(page).to have_selector('.atwho-container', visible: false)
+    end
+
     it 'doesn\'t wrap for assignee values' do
       note = find('#note_note')
       page.within '.timeline-content-form' do