Add tests for autocomplete on a Issue

spec/features/participants_autocomplete_spec.rb

+require 'spec_helper'
+
+feature 'Member autocomplete', feature: true do
+  let(:project) { create(:project, :public) }
+  let(:user) { create(:user) }
+  let(:participant) { create(:user) }
+  let(:author) { create(:user) }
+  let(:issue) { create(:issue, author: author, project: project) }
+
+  before do
+    login_as user
+  end
+
+  describe 'On a Issue', js: true do
+    before do
+      create(:note, note: 'ultralight beam', noteable: issue, author: participant)
+      visit_issue(project, issue)
+    end
+
+    describe 'adding a new note' do
+      describe 'when typing @' do
+
+        before do
+          sleep 1
+          page.within('.new-note') do
+            sleep 1
+            find('#note_note').native.send_keys('@')
+          end
+        end
+
+        it 'suggestions are displayed' do
+          expect(page).to have_selector('.atwho-view', visible: true)
+        end
+
+        it 'author is a suggestion' do
+          page.within('.atwho-view', visible: true) do
+            expect(page).to have_content(author.username)
+          end
+        end
+
+        it 'participant is a suggestion' do
+          page.within('.atwho-view', visible: true) do
+            expect(page).to have_content(participant.username)
+          end
+        end
+      end
+    end
+  end
+
+  def visit_issue(project, issue)
+    visit namespace_project_issue_path(project.namespace, project, issue)
+  end
+end