TDD functions revised (added chance to run a single test)

gistfile1.el

(defun mocha-run(test-file)
  "Runs all the tests in the passed file"
  (interactive "b")
  (let* (command result exit-value)
    (setq command (concat "mocha -r should --globals i --timeout 10000 " test-file))
    (setq exit-value (shell-command command))
    (color-modeline test-file)))
(defun color-modeline(test-file)
  "Colors the modeline, green success red failure"
  (interactive)
  (let (test-result-color)
    (if (= exit-value 0)
        (progn
          (setq test-result-color "Green")
          (run-at-time "1 sec" nil 'no-color-modeline))
      (setq test-result-color "Red"))
    (set-face-background 'modeline test-result-color))) 
(defun no-color-modeline()
  "No color for the modeline"
  (interactive)
  (set-face-background 'modeline nil)) 
(global-set-key (kbd "C-c C-r") 'mocha-run)

(defun mocha-test-region (start end)
  "Runs mocha on a region, useful to run tests on single functions and not on an entire file; does this by creating a file running mocha on it and then deleting it, for sure not the best way but it's working and for now I'm fine"
  (interactive "r")
  (setq filename "mocha-test-region.js")
  (write-region start end filename)
  (mocha-run (expand-file-name filename))
  (delete-file filename)
  )
(global-set-key (kbd "C-c C-j") 'mocha-test-region)