toggle-file.el

(require 's)
 (defun rlb3/toggle-file ()
   (interactive)
   (let* ((full-path (buffer-file-name))
          (path (rlb3/remove-ulc full-path))
          (file-type (rlb3/determine-file-type path)))
     (if (eq file-type 'test)
         (rlb3/jump-to-related-test path)
       (rlb3/jump-to-related-module path))))

 (defun rlb3/remove-ulc (path)
   (let ((new-path (s-chop-prefix "/usr/local/cpanel/" path )))
     new-path))

 (defun rlb3/determine-file-type (path)
   (cond ((s-ends-with? ".pm" full-path) 'test)
         ((s-ends-with? ".t" full-path) 'module)))

 (defun rlb3/jump-to-related-test (path)
   (find-file path))

 (rlb3/determine-file-type (rlb3/remove-ulc "/usr/local/cpanel/t/Cpanel-SSLInstall.t"))
 (rlb3/determine-file-type (rlb3/remove-ulc "/usr/local/cpanel/Cpanel/SSLInstall.pm"))