Add spec for saving filtered item in dropdown

spec/features/issues/issue_sidebar_spec.rb

@@ -57,6 +57,23 @@ feature 'Issue Sidebar', feature: true do
         expect(page.find('.dropdown-menu-user-link.is-active')).to have_content(user.name)
       end
     end
+
+    it 'keeps your filtered term after filtering and dismissing the dropdown' do
+      find('.dropdown-input-field').native.send_keys user2.name
+
+      wait_for_ajax
+
+      page.within '.dropdown-menu-user' do
+        expect(page).not_to have_content 'Unassigned'
+        click_link user2.name
+      end
+
+      find('.js-right-sidebar').click
+      find('.block.assignee .edit-link').click
+
+      expect(page.all('.dropdown-menu-user li').length).to eq(1)
+      expect(find('.dropdown-input-field').value).to eq(user2.name)
+    end
   end
 
   context 'as a allowed user' do