How to make a temporary directory that gets deleted once the body is finished?

Question

Is there a way to temporarily create a new directory, then remove it when the body of the code has finished?

(with-temp-directory path
   (write-test-files-into path)
   (other-test-functions path))
;; path is now deleted!

Similar to the Python function tempfile.TemporaryDirectory by a similar name:

# create a temporary directory using the context manager
with tempfile.TemporaryDirectory() as tmpdirname:
    print('created temporary directory', tmpdirname)

Answer 1

make-temp-file can be used to make a directory instead of a file, this example simply calls make-temp-file, then removes the directory afterwards.

(let ((temp-dir (make-temp-file "foo" t)))
  (unwind-protect
      (progn
        ;; do stuff
        )
    (delete-directory temp-dir t)))

This same functionality as a macro:

(defmacro with-temp-dir (temp-dir &rest body)
  `(let ((,temp-dir (make-temp-file "" t)))
    (unwind-protect
      (progn
        ,@body)
      (delete-directory ,temp-dir t))))

Answer 2

;; Inspired from `dired-create-directory` code.
(defun with-temp-dir (dir)
  "..."
  (let* ((expanded  (directory-file-name (expand-file-name dir)))
         (try       expanded)
         new)
    (unwind-protect
        (progn
          (when (file-exists-p expanded)
            (error "Cannot create directory %s: file exists" expanded))
          ;; Find the topmost nonexistent parent dir (variable `new')
          (while (and try  (not (file-exists-p try))  (not (equal new try)))
            (setq new  try
                  try  (directory-file-name (file-name-directory try))))
          (make-directory expanded t)
          (write-test-files expanded)
          (other-test-functions expanded))
      (delete-directory new t))))

Or if you want to do arbitrary things in the directory, not just write-test-files and other-test-functions, use a macro:

(defmacro with-temp-dir (dir &rest body)
  "..."
  `(let* ((expanded  (directory-file-name (expand-file-name ',dir)))
          (try       expanded)
          new)
     (unwind-protect
         (progn
           (when (file-exists-p expanded)
             (error "Cannot create directory %s: file exists" expanded))
           ;; Find the topmost nonexistent parent dir (variable `new')
           (while (and try  (not (file-exists-p try))  (not (equal new try)))
             (setq new  try
                   try  (directory-file-name (file-name-directory try))))
           (make-directory expanded t)
           ,@body)
       (delete-directory new t))))

Then you would do, e.g.:

(with-temp-dir "/your/temp/dir" (write-test-files ...) (other-test-functions ...))