test(capybara-helpers): add no results search helper

Author: difernandez

spec/support/capybara_helpers.rb

@@ -99,6 +99,12 @@ def expect_slimselect_result_text_to_eq(result_number, text)
     )
   end
 
+  def expect_slimselect_no_result
+    expect(page).to have_css(
+      "div.ss-search", text: 'No Result'
+    )
+  end
+
   def expect_slimselect_error(text)
     expect(page).to have_css(".ss-error", text: text)
   end