Examine failed test using ediff to compare actual and expected results

gistfile1.el

(defvar clojure-test-ediff-buffers nil)
(defun clojure-test-ediff-cleanup ()
  "A function for ediff-cleanup-hook, to cleanup the temporary ediff buffers"
  (mapc #'kill-buffer clojure-test-ediff-buffers))

(defconst re1
  "Expected \\(?:.\\|\n\\)*, got (not ([^ ]+ \\(\"\\(?:.\\|\n\\)+\"\\) \\(\"\\(?:.\\|\n\\)+\"\\)))"
  "Match predicate on strings test")
(defconst re2
  "Expected \\(?:.\\|\n\\)*, got (not ([^ ]+ \\(\\(?:.\\|\n\\)+\\) \\(\\(?:.\\|\n\\)+\\)))"
  "Match predicate test")
(defconst re3 "Expected \\(\\(?:.\\|\n\\)+\\), got \\(\\(?:.\\|\n\\)+\\)"
  "Match general test")

(defun clojure-test-ediff-result ()
  "Show the result of the test under point as an ediff"
  (interactive)
  (let ((overlay (find-if (lambda (o) (overlay-get o 'message))
                          (overlays-at (point)))))
    (if overlay
        (let* ((m (overlay-get overlay 'message))
               (f (or (string-match re1 m)
                      (string-match re2 m)
                      (string-match re3 m))))
          (message m)
          (if f
              (let ((exp-buffer (generate-new-buffer " *expected*"))
                    (act-buffer (generate-new-buffer " *actual*")))
                (with-current-buffer exp-buffer
                  (insert (match-string-no-properties 1 m)))
                (with-current-buffer act-buffer
                  (insert (match-string-no-properties 2 m)))
                (setq clojure-test-ediff-buffers
                      (list (buffer-name exp-buffer) (buffer-name act-buffer)))
                (ediff-buffers
                 (buffer-name exp-buffer) (buffer-name act-buffer)))
            (message "Error, regex failed to match"))))))