Use lexical-binding in dig.el and add tests

* lisp/net/dig.el: Use lexical-binding.
(dig-program, dig-dns-server, dig-font-lock-keywords): Remove
redundant :group args.
* test/lisp/net/dig-tests.el: New file.

2 files changed, 60 insertions, 7 deletions

diff --git a/lisp/net/dig.el b/lisp/net/dig.el
index 852d8ae0491..f36999119f2 100644
--- a/lisp/net/dig.el
+++ b/lisp/net/dig.el
@@ -1,4 +1,4 @@
-;;; dig.el --- Domain Name System dig interface
+;;; dig.el --- Domain Name System dig interface  -*- lexical-binding:t -*-
 
 ;; Copyright (C) 2000-2020 Free Software Foundation, Inc.
 
@@ -42,15 +42,13 @@
 
 (defcustom dig-program "dig"
   "Name of dig (domain information groper) binary."
-  :type 'file
-  :group 'dig)
+  :type 'file)
 
 (defcustom dig-dns-server nil
   "DNS server to query.
 If nil, use system defaults."
   :type '(choice (const :tag "System defaults")
-                 string)
-  :group 'dig)
+                 string))
 
 (defcustom dig-font-lock-keywords
   '(("^;; [A-Z]+ SECTION:" 0 font-lock-keyword-face)
@@ -58,8 +56,7 @@ If nil, use system defaults."
     ("^; <<>>.*" 0 font-lock-type-face)
     ("^;.*" 0 font-lock-function-name-face))
   "Default expressions to highlight in dig mode."
-  :type 'sexp
-  :group 'dig)
+  :type 'sexp)
 
 (defun dig-invoke (domain &optional
                           query-type query-class query-option
diff --git a/test/lisp/net/dig-tests.el b/test/lisp/net/dig-tests.el
new file mode 100644
index 00000000000..1b14384634e
--- /dev/null
+++ b/test/lisp/net/dig-tests.el
@@ -0,0 +1,56 @@
+;;; dig-tests.el --- Tests for dig.el  -*- lexical-binding:t -*-
+
+;; Copyright (C) 2020 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/>.
+
+;;; Commentary:
+
+;;; Code:
+
+(require 'ert)
+(require 'dig)
+
+(defvar dig-test-result-data "
+; <<>> DiG 9.11.16-2-Debian <<>> gnu.org
+;; global options: +cmd
+;; Got answer:
+;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 7777
+;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
+
+;; OPT PSEUDOSECTION:
+; EDNS: version: 0, flags:; udp: 4096
+;; QUESTION SECTION:
+;gnu.org.                       IN      A
+
+;; ANSWER SECTION:
+gnu.org.                300     IN      A       111.11.111.111
+
+;; Query time: 127 msec
+;; SERVER: 192.168.0.1#53(192.168.0.1)
+;; WHEN: Sun Apr 26 00:47:55 CEST 2020
+;; MSG SIZE  rcvd: 52
+
+" "Data used to test dig.el.")
+
+(ert-deftest dig-test-dig-extract-rr ()
+  (with-temp-buffer
+    (insert dig-test-result-data)
+    (should (equal (dig-extract-rr "gnu.org")
+                   "gnu.org.            300     IN      A       111.11.111.111"))))
+
+(provide 'dig-tests)
+;;; dig-tests.el ends here