How to force Yes/y answer to `emacs has changed since visited or saved. Save anyway?` prompt

Question

I am working in a git-repo using zsh shell.

On the background, git-auto-fetch plugin is running in order to automatically fetch all changes from all remotes while I am working in a git-initialized directory.

Due to this, if the buffer I am using in emacs is touched or changed the file behind my back:

• I am first asked: emacs has changed since visited or saved. Save anyway? #> Yes

• Than asked again: example_file.py changed on disk; really edit the buffer? (y, n, r or C-h) #> y

---

Would it be possible to prevent:

• emacs has changed since visited or saved. Save anyway?
• example_file.py changed on disk; really edit the buffer? (y, n, r or C-h)

messages to show up by default and force to make their answer Yes/y?

---

my save function:

(defun my-save-all ()
       (interactive)
       (let ((message-log-max nil)
             (inhibit-message t))
         (save-some-buffers t)))

(defun save-all ()
  (interactive)
  (my-save-all)
  (bk-kill-buffers "__init__.py")
  (bk-kill-buffers "*helm"))

Answer 1

You might want to check the auto-answer package. It works on functions whose the underlying prompt is yes-or-no-p, read-string, read-from-minibuffer, read-key-sequence, read-key-sequence-vector, read-event , read-passwd or lastly read-multiple-choice.

It's pretty easy to use. Just bind auto-answer to a list of (REGEXP ANSWER):

;; Example usage:
;; (let ((auto-answer '(("\\`What's your name\\? \\'" "jack")
;;                      ("\\`What's your password\\? \\'" "secr3t"))))
;;   (list
;;    (read-string "What's your name? ")
;;    (read-passwd "What's your password? ")))
;; => ("jack" "secr3t")

Hence, in your case, you could do something like this (not tested):

(let ((auto-answer
       '((".*has changed since visited or saved. Save anyway\\?" t)
         (".*changed on disk; really edit the buffer\\?.*" ?y))
     ...
)))

I have read the source code of save-some-buffers, so I'm sure that the first prompt is a yes-or-no-p (thus the answer t), though it's rather obvious. I'm not sure about the second prompt, but it is most likely a read-multiple-choice. If not, you have to figure it out and change the answer accordingly.

auto-answer is currently not on Melpa. You can install it with quelpa-use-package:

(use-package auto-answer
  :quelpa (auto-answer :fetcher github :repo "YoungFrog/auto-answer")
  :ensure t)

or just with quelpa (which is available on Melpa):

(quelpa '(auto-answer :fetcher github :repo "YoungFrog/auto-answer"))

Answer 2

Based on an example from the emacs wiki, the following works for me to force Emacs to overwrite external changes to the file:

(defadvice basic-save-buffer (around auto-confirm compile activate)
  (cl-letf (((symbol-function 'yes-or-no-p) (lambda (&rest args) t))
            ((symbol-function 'y-or-n-p) (lambda (&rest args) t)))
    ad-do-it))