         '("Test.js" "_test.js" "-test.js")))
 
 (defun looks-like-test-file-name (file-name)
-  (_any (_partial 's-ends-with-p file-name)
-        (possible-test-file-suffixes)))
+  (!!any? (s-ends-with-p it file-name) (possible-test-file-suffixes)))
 
 (defun jump-to-source-file-other-window (arg)
   (interactive "P")

    (if (file-exists-p file) file nil)))

(defun test-file-name (suffix)
  (format "%s/%s%s.js" (js2r-chop-suffix (guess-test-folder) "/") (test-file-name-stub) suffix))

(defun test-file-name-stub ()
  (js2r-chop-suffix (file-name-nondirectory (buffer-file-name)) ".js"))

(defun guess-test-folder ()
  (let ((source-dir (file-name-directory (buffer-file-name))))

        (find-file-other-window file)
      (error "%s not found." file))))

(defun guess-source-file ()
  (unless (looks-like-test-file-name (buffer-file-name))
    (error "This doesn't look like a test file."))
  (format "%s/%s.js" (s-chop-suffix "/" (guess-source-folder)) (guess-source-file-name)))

(defun guess-source-file-name ()
  (s-chop-suffixes (possible-test-file-suffixes) (file-name-nondirectory (buffer-file-name))))

(defun guess-source-folder ()
  (let ((test-dir (file-name-directory (buffer-file-name))))
