My Emacs git-gutter configuration, paraphrased

git-gutter.el

(defconst doom-fringe-size '3 "Default fringe width")

;;; Setting up the fringe
;; switches order of fringe and margin
(setq-default fringes-outside-margins t)

;; standardize fringe width
(fringe-mode doom-fringe-size)
(push `(left-fringe  . ,doom-fringe-size) default-frame-alist)
(push `(right-fringe . ,doom-fringe-size) default-frame-alist)

;;; Setting up git-gutter
(require 'git-gutter)
(require 'git-gutter-fringe)

;; colored fringe "bars"
(define-fringe-bitmap 'git-gutter-fr:added
  [224 224 224 224 224 224 224 224 224 224 224 224 224 224 224 224 224 224 224 224 224 224 224 224 224]
  nil nil 'center)
(define-fringe-bitmap 'git-gutter-fr:modified
  [224 224 224 224 224 224 224 224 224 224 224 224 224 224 224 224 224 224 224 224 224 224 224 224 224]
  nil nil 'center)
(define-fringe-bitmap 'git-gutter-fr:deleted
  [0 0 0 0 0 0 0 0 0 0 0 0 0 128 192 224 240 248]
  nil nil 'center)
  
;; Bootstrap
(add-hook 'text-mode 'git-gutter-mode)
(add-hook 'prog-mode 'git-gutter-mode)
(add-hook 'conf-mode 'git-gutter-mode)