;;; mumi -- Mediocre, uh, mail interface
;;; Copyright © 2020 Ricardo Wurmus <rekado@elephly.net>
;;;
;;; This program is free software: you can redistribute it and/or
;;; modify it under the terms of the GNU Affero General Public License
;;; as published by the Free Software Foundation, either version 3 of
;;; the License, or (at your option) any later version.
;;;
;;; This program is distributed in the hope that it will be useful,
;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
;;; Affero General Public License for more details.
;;;
;;; You should have received a copy of the GNU Affero General Public
;;; License along with this program.  If not, see
;;; <http://www.gnu.org/licenses/>.

(define-module (mumi test-utils)
  #:use-module (mumi xapian)
  #:use-module (srfi srfi-19)
  #:use-module (srfi srfi-64)
  #:use-module (ice-9 ftw)
  #:export (delete-file-recursively mock))

(define* (delete-file-recursively dir)
  "Delete DIR recursively, like `rm -rf', without following symlinks.
Report but ignore errors."
  (let ((dev (stat:dev (lstat dir))))
    (file-system-fold (lambda (dir stat result)    ; enter?
                        (= dev (stat:dev stat)))
                      (lambda (file stat result)   ; leaf
                        (delete-file file))
                      (const #t)              ; down
                      (lambda (dir stat result)    ; up
                        (rmdir dir))
                      (const #t)              ; skip
                      (lambda (file stat errno result)
                        (format (current-error-port)
                                "warning: failed to delete ~a: ~a~%"
                                file (strerror errno)))
                      #t
                      dir

                      ;; Don't follow symlinks.
                      lstat)))

(define-syntax-rule (mock (module proc replacement) body ...)
  "Within BODY, replace the definition of PROC from MODULE with the definition
given by REPLACEMENT."
  (let* ((m (resolve-module 'module))
         (original (module-ref m 'proc)))
    (dynamic-wind
      (lambda () (module-set! m 'proc replacement))
      (lambda () body ...)
      (lambda () (module-set! m 'proc original)))))