Find node project root (first parent folder with a package.json)

find-node-project-root.elisp

(defun get-node-project-dir ()
  "Find first parent folder with package.json"
  (setq project_dir ".")
  (while (and
	  (not (eq nil project_dir))
	  (not (string= project_dir "/"))
	  (eq nil (member "package.json" (directory-files project_dir)))
	  )
    (setq project_dir (expand-file-name (concat project_dir "/.."))))

  (if (member "package.json" (directory-files project_dir))
	      project_dir
	      nil)
  )