Install

(package-install-file "ert-extras.el")

Use

(require 'ert-extras.el)

are macro

(ert-deftest addition-works-as-expected ()
  (are
   (= 2 (+ 1 1))
   (= 5 (+ 2 3))
   (= 23 (+ 17 (* 2 3)))))

Test

M-x load-file test-ert-extras.el
M-x ert-run-tests-interactively