Emacs: Format JavaScript Code 🚀

By Xah Lee. Date: . Last updated: .

put this in your Emacs Init File:

(defun xah-js-format-buffer ()
  "Format JavaScript/TypeScript code of current buffer.
Buffer is saved first.
This command requires external command deno.

URL `http://xahlee.info/emacs/emacs/emacs_format_js_code.html'
Created: 2020-09-23
Version: 2024-12-22"
  (interactive)
  (let ((xoutbuf (get-buffer-create "*xah-js-format output*")))
    (when (not buffer-file-name) (user-error "buffer %s is not a file." (buffer-name)))
    (save-current-buffer (set-buffer xoutbuf) (erase-buffer))
    (when (buffer-modified-p) (save-buffer))
    (call-process "deno" nil xoutbuf nil "fmt" "-q" buffer-file-name)
    (if (eq 1 (save-current-buffer (set-buffer xoutbuf) (point-max)))
        (progn
          (kill-buffer xoutbuf)
          (revert-buffer t t t))
      (display-buffer xoutbuf))))

part of Emacs: Xah JS Mode (JavaScript) 📦

Emacs, Format Code