From f2969e568b579e49dbe2f73cbf9961d5f32503aa Mon Sep 17 00:00:00 2001 From: Matt Armstrong Date: Mon, 15 Feb 2021 12:59:08 -0800 Subject: [PATCH 1/2] Add test coverage for src/filelock.c (Bug#46397) * test/src/filelock-tests.el: New file. --- test/src/filelock-tests.el | 173 +++++++++++++++++++++++++++++++++++++ 1 file changed, 173 insertions(+) create mode 100644 test/src/filelock-tests.el diff --git a/test/src/filelock-tests.el b/test/src/filelock-tests.el new file mode 100644 index 0000000000..c6f55efd49 --- /dev/null +++ b/test/src/filelock-tests.el @@ -0,0 +1,173 @@ +;;; filelock-tests.el --- test file locking -*- lexical-binding: t; -*- + +;; Copyright (C) 2021 Free Software Foundation, Inc. + +;; This file is part of GNU Emacs. + +;; GNU Emacs is free software; you can redistribute it and/or modify +;; it under the terms of the GNU General Public License as published by +;; the Free Software Foundation, either version 3 of the License, or +;; (at your option) any later version. + +;; GNU Emacs 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 General Public License for more details. + +;; You should have received a copy of the GNU General Public License +;; along with this program. If not, see . + +;;; Commentary: + +;; This file tests code in src/filelock.c and, to some extent, the +;; related code in src/fileio.c. +;; +;; See also (info "(emacs)Interlocking") and (info "(elisp)File Locks") + +;;; Code: + +(require 'cl-macs) +(require 'ert) +(require 'seq) + +(defun filelock-tests--fixture (test-function) + "Call TEST-FUNCTION under a test fixture. +Create a test directory and a buffer whose `buffer-file-name' and +`buffer-file-truename' are a file within it, then call +TEST-FUNCTION. Finally, delete the buffer and the test +directory." + (let* ((temp-dir (make-temp-file "filelock-tests" t)) + (name (concat (file-name-as-directory temp-dir) + "userfile")) + (create-lockfiles t)) + (unwind-protect + (with-temp-buffer + (setq buffer-file-name name + buffer-file-truename name) + (unwind-protect + (save-current-buffer + (funcall test-function)) + ;; Set `buffer-file-truename' nil to prevent unlocking, + ;; which might prompt the user and/or signal errors. + (setq buffer-file-name nil + buffer-file-truename nil))) + (delete-directory temp-dir t nil)))) + +(defun filelock-tests--make-lock-name (file-name) + "Return the lock file name for FILE-NAME. +Equivalent logic in Emacs proper is implemented in C and +unavailable to Lisp." + (concat (file-name-directory (expand-file-name file-name)) + ".#" + (file-name-nondirectory file-name))) + +(defun filelock-tests--spoil-lock-file (file-name) + "Spoil the lock file for FILE-NAME. +Cause Emacs to report errors for various file locking operations +on FILE-NAME going forward. Create a file that is incompatible +with Emacs' file locking protocol, but uses the same name as +FILE-NAME's lock file. A directory file is used, which is +portable in practice." + (make-directory (filelock-tests--make-lock-name file-name))) + +(defun filelock-tests--unspoil-lock-file (file-name) + "Remove the lock file spoiler for FILE-NAME. +See `filelock-tests--spoil-lock-file'." + (delete-directory (filelock-tests--make-lock-name file-name) t)) + +(defun filelock-tests--should-be-locked () + "Abort the current test if the current buffer is not locked. +Exception: on systems without lock file support, aborts the +current test if the current file is locked (which should never +the case)." + (if (eq system-type 'ms-dos) + (should-not (file-locked-p buffer-file-truename)) + (should (file-locked-p buffer-file-truename)))) + +(ert-deftest filelock-tests-lock-unlock-no-errors () + "Check that locking and unlocking works without error." + (filelock-tests--fixture + (lambda () + (should-not (file-locked-p (buffer-file-name))) + + ;; inserting text should lock the buffer's file. + (insert "this locks the buffer's file") + (filelock-tests--should-be-locked) + (unlock-buffer) + (set-buffer-modified-p nil) + (should-not (file-locked-p (buffer-file-name))) + + ;; `set-buffer-modified-p' should lock the buffer's file. + (set-buffer-modified-p t) + (filelock-tests--should-be-locked) + (unlock-buffer) + (should-not (file-locked-p (buffer-file-name))) + + (should-not (file-locked-p (buffer-file-name)))))) + +(ert-deftest filelock-tests-lock-spoiled () + "Check `lock-buffer' ." + (skip-unless (not (eq system-type 'ms-dos))) ; no filelock support + (filelock-tests--fixture + (lambda () + (filelock-tests--spoil-lock-file buffer-file-truename) + ;; FIXME: errors when locking a file are ignored; should they be? + (set-buffer-modified-p t) + (filelock-tests--unspoil-lock-file buffer-file-truename) + (should-not (file-locked-p buffer-file-truename))))) + +(ert-deftest filelock-tests-file-locked-p-spoiled () + "Check that `file-locked-p' fails if the lockfile is \"spoiled\"." + (skip-unless (not (eq system-type 'ms-dos))) ; no filelock support + (filelock-tests--fixture + (lambda () + (filelock-tests--spoil-lock-file buffer-file-truename) + (let ((err (should-error (file-locked-p (buffer-file-name))))) + (should (equal (seq-subseq err 0 2) + '(file-error "Testing file lock"))))))) + +(ert-deftest filelock-tests-unlock-spoiled () + "Check that `unlock-buffer' fails if the lockfile is \"spoiled\"." + (skip-unless (not (eq system-type 'ms-dos))) ; no filelock support + (filelock-tests--fixture + (lambda () + ;; Set the buffer modified with file locking temporarily + ;; disabled. + (let ((create-lockfiles nil)) + (set-buffer-modified-p t)) + (should-not (file-locked-p buffer-file-truename)) + (filelock-tests--spoil-lock-file buffer-file-truename) + + ;; FIXME: Unlocking buffers should not signal errors related to + ;; their lock files (bug#46397). + (let ((err (should-error (unlock-buffer)))) + (should (equal (cl-subseq err 0 2) + '(file-error "Unlocking file"))))))) + +(ert-deftest filelock-tests-kill-buffer-spoiled () + "Check that `kill-buffer' fails if a lockfile is \"spoiled\"." + (skip-unless (not (eq system-type 'ms-dos))) ; no filelock support + (filelock-tests--fixture + (lambda () + ;; Set the buffer modified with file locking temporarily + ;; disabled. + (let ((create-lockfiles nil)) + (set-buffer-modified-p t)) + (should-not (file-locked-p buffer-file-truename)) + (filelock-tests--spoil-lock-file buffer-file-truename) + + ;; Kill the current buffer. Because the buffer is modified Emacs + ;; will attempt to unlock it. Temporarily bind `yes-or-no-p' to + ;; a function that fakes a "yes" answer for the "Buffer modified; + ;; kill anyway?" prompt. + ;; + ;; FIXME: Killing buffers should not signal errors related to + ;; their lock files (bug#46397). + (let* ((err (cl-letf (((symbol-function 'yes-or-no-p) + (lambda (&rest _) t))) + (should-error (kill-buffer))))) + (should (equal (seq-subseq err 0 2) + '(file-error "Unlocking file"))))))) + +(provide 'filelock-tests) +;;; filelock-tests.el ends here -- 2.30.1