Use lexical-binding in po.el and add tests

* lisp/textmodes/po.el: Use lexical-binding.

* test/lisp/textmodes/po-tests.el: New file with tests for po.el.

2 files changed, 69 insertions, 1 deletions

diff --git a/lisp/textmodes/po.el b/lisp/textmodes/po.el
index d5645e86304..29c6d3f4608 100644
--- a/lisp/textmodes/po.el
+++ b/lisp/textmodes/po.el
@@ -1,4 +1,4 @@
-;;; po.el --- basic support of PO translation files
+;;; po.el --- basic support of PO translation files  -*- lexical-binding:t -*-
 
 ;; Copyright (C) 1995-1998, 2000-2020 Free Software Foundation, Inc.
 
diff --git a/test/lisp/textmodes/po-tests.el b/test/lisp/textmodes/po-tests.el
new file mode 100644
index 00000000000..a098290ce15
--- /dev/null
+++ b/test/lisp/textmodes/po-tests.el
@@ -0,0 +1,68 @@
+;;; po-tests.el --- Tests for po.el                  -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2020 Free Software Foundation, Inc.
+
+;; Author: Simen Heggestøyl <simenheg@gmail.com>
+;; Keywords:
+
+;; 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/>.
+
+;;; Commentary:
+
+;;
+
+;;; Code:
+
+(require 'po)
+(require 'ert)
+
+(defconst po-tests--buffer-string
+  "# Norwegian bokmål translation of the GIMP.
+# Copyright (C) 1999-2001 Free Software Foundation, Inc.
+#
+msgid \"\"
+msgstr \"\"
+\"Project-Id-Version: gimp 2.8.5\\n\"
+\"Report-Msgid-Bugs-To: https://gitlab.gnome.org/GNOME/gimp/issues\\n\"
+\"POT-Creation-Date: 2013-05-27 14:57+0200\\n\"
+\"PO-Revision-Date: 2013-05-27 15:21+0200\\n\"
+\"Language: nb\\n\"
+\"MIME-Version: 1.0\\n\"
+\"Content-Type: text/plain; charset=UTF-8\\n\"
+\"Content-Transfer-Encoding: 8bit\\n\"
+\"Plural-Forms: nplurals=2; plural=(n != 1);\\n\"
+
+#: ../desktop/gimp.desktop.in.in.h:1 ../app/about.h:26
+msgid \"GNU Image Manipulation Program\"
+msgstr \"GNU bildebehandlingsprogram\"
+")
+
+(ert-deftest po-tests-find-charset ()
+  (with-temp-buffer
+    (insert po-tests--buffer-string)
+    (should (equal (po-find-charset (cons nil (current-buffer)))
+                   "UTF-8"))))
+
+(ert-deftest po-tests-find-file-coding-system-guts ()
+  (with-temp-buffer
+    (insert po-tests--buffer-string)
+    (should (equal (po-find-file-coding-system-guts
+                    'insert-file-contents
+                    (cons "*tmp*" (current-buffer)))
+                   '(utf-8 . nil)))))
+
+(provide 'po-tests)
+;;; po-tests.el ends here