Let switch-to-buffer to already open buffer switch to that window, rather than open it in this one

Question

Is there a way to make switch-to-buffer more dwim in this regard? Let's say I have two windows with foo.el and bar.el open. With my point in foo.el, if I switch-to-buffer and open bar.el, I'd like to just be taken to the other window, rather than be left with two windows of bar.el.

Answer 1

(defun my-switch-to-buffer (buffer)
  "Display BUFFER in the selected window.
If BUFFER is displayed in an existing window, select that window instead."
  (interactive
   (list (get-buffer (read-buffer
                      "Switch to buffer: "
                      (other-buffer (current-buffer))))))
  (if-let ((win (get-buffer-window buffer)))
      (select-window win)
    (switch-to-buffer buffer)))

---

Update: while defining a new command is a clear and clean solution, advising switch-to-buffer will make switch-to-buffer and other commands which call switch-to-buffer (such as ido-switch-buffer and helm-buffers-list) have the new behavior.

(defun switch-to-buffer--hack (orig-fun &rest args)
  (if-let ((win (get-buffer-window (car args))))
      (select-window win)
    (apply orig-fun args)))

(advice-add 'switch-to-buffer :around #'switch-to-buffer--hack)

(This doesn't work with Ivy's ivy-switch-buffer for some reason)