Add test to time-stamp.el

test/lisp/time-stamp-tests.el

+;;; time-stamp-tests.el --- tests for time-stamp.el -*- lexical-binding: t -*-
+
+;; Copyright (C) 2019 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 GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
+
+;;; Code:
+
+(require 'ert)
+(require 'time-stamp)
+
+(defun test-stamp (ts-format time)
+  (time-stamp--format (time-stamp-string-preprocess ts-format time) time))
+
+(ert-deftest test-time-stamp ()
+  (let ((user-login-name "foo")
+        (time-stamp-time-zone t)
+	(time '(23847 24475 657815 318000))
+	(format "%:y-%02m-%02d %02H:%02M:%02S %u"))
+    (should (equal (test-stamp format time)
+                   "2019-07-11 16:11:07 foo"))))
+
+;;; time-stamp-tests.el ends here