This is a version of perltidy.el that has been modified so that it can find the closest .perltidyrc to use (thanks Zakame), and the ability to format on-save for perl-mode and cperl-mode.

(straight-use-package
 '(perltidy
   :type git
   :host github
   :repo "perl-ide/perltidy.el"
   :branch "master"))

(require 'perltidy)
(setq perltidy-on-save t)