(require 'package)
(add-to-list 'package-archives '("melpa" . "https://melpa.org/packages/"))
(package-refresh-contents)
(package-initialize)

(unless (package-installed-p 'ivy)
  (package-install 'ivy))
(unless (package-installed-p 'yasnippet-snippets)
  (package-install 'yasnippet-snippets))

(require 'yasnippet)
(require 'ivy)

(yas-reload-all)

(switch-to-buffer "*scratch*")
(lisp-interaction-mode)
(yas-minor-mode-on)

(let ((templates (mapcar #'yas--template-key
                         (yas--all-templates (yas--get-snippet-tables)))))
  (defun update-fn ()
    (with-current-buffer "*scratch*"
      (save-restriction
        (narrow-to-region 3 3)
        (insert " " (ivy-state-current ivy-last))
        (yas-expand)
        (mapc #'yas-abort-snippet (yas-active-snippets)))
      (redisplay)))
  (let ((buffer-undo-list t))
    (while t
      (erase-buffer)
      (insert "aaaaaa")
      (redisplay)
      (sit-for 0.1)
      (run-with-timer
       0.01 nil (lambda ()
                  (dotimes (_ (% (random) 15))
                    (execute-kbd-macro "\C-n")
                    (sit-for 0.05)
                    (redisplay)
                    (when (zerop (% (random) 4))
                      (execute-kbd-macro "\C-p")
                      (sit-for 0.05)
                      (redisplay)))
                  (sit-for 0.1)
                  (redisplay)
                  (abort-recursive-edit)))
      (catch 'exit
        (condition-case err
            (ivy-read "foo: " templates
                      :update-fn #'update-fn)
          (quit))))))