Add: emms-tracktag wrapper for the audiotools program

http://audiotools.sourceforge.net/ provides a tool `tracktag`
which handles writing tags for several different audio formats,
including Opus. this patch provides a very basic wrapper to interface
between EMMS track info and tracktag metadata. It also configures
emms-tag-editor.el to use it for writing tags to Opus files.

Add: test.sh and test/test-all.el

Basic setup to run ert tests from the terminal using Emacs in batch
mode. This should load up only ERT, the tests in the test/ directory
and their dependencies.

Add: opus extension to emms-libtag-known-extensions

libtag works as a reader for opus files, this just ads the opus
extension to the regexp list.

1 files changed, 101 insertions, 0 deletions

diff --git a/test/emms-tracktag-test.el b/test/emms-tracktag-test.el
new file mode 100644
index 0000000..9b66d5e
--- /dev/null
+++ b/test/emms-tracktag-test.el
@@ -0,0 +1,101 @@
+;; emms-tracktag-test.el --- Unit tests for emms-tracktag module  -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2021  Grant Shoshin Shangreaux
+
+;; Author: Grant Shoshin Shangreaux <grant@churls.world>
+;; Keywords:
+
+;; This program 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.
+
+;; 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 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 <https://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; Tests for emms-tracktag.el
+
+;;; Code:
+
+(require 'emms)
+(require 'emms-tracktag)
+
+(ert-deftest emms-tracktag--map-track-info-test ()
+  "Ensure mapping of emms info to tracktag fields is correct."
+  (let ((track '(*track*
+                 (type . file) (name . "foo")
+                 (info-album . "The Sounds of the Sounds of Science")
+                 (info-artist . "Yo La Tengo")
+                 (info-title . "Sea Urchins")
+                 (info-date . "2020")
+                 (info-tracknumber . "1")))
+        (track2 '(*track*
+                  (info-composer . "Ira Kaplan, Georgia Hubley, James Mcnew")
+                  (info-performer . "Yo La Tengo")
+                  (info-year . "2002")
+                  (info-discnumber . "1")
+                  (info-note . "new soundtrack to an old film"))))
+    (should (seq-set-equal-p
+             '((album . "The Sounds of the Sounds of Science")
+               (artist . "Yo La Tengo")
+               (name . "Sea Urchins")
+               (year . "2020")
+               (number . "1"))
+             (emms-tracktag--map-track-info track)))
+    (should (seq-set-equal-p
+             '((composer . "Ira Kaplan, Georgia Hubley, James Mcnew")
+               (performer . "Yo La Tengo")
+               (year . "2002")
+               (album-number . "1")
+               (comment . "new soundtrack to an old film"))
+             (emms-tracktag--map-track-info track2)))))
+
+(ert-deftest emms-tracktag--build-args-test ()
+  "Ensure args for tracktag are properly formed."
+  (let ((track '(*track*
+                 (type . file) (name . "foo.flac")
+                 (info-album . "The Sounds of the Sounds of Science")
+                 (info-artist . "Yo La Tengo")
+                 (info-title . "Sea Urchins")
+                 (info-date . "2020")
+                 (info-tracknumber . "1")
+                 (info-composer . "Ira Kaplan, Georgia Hubley, James Mcnew")
+                 (info-performer . "Yo La Tengo")
+                 (info-discnumber . "1")
+                 (info-note . "new soundtrack to an old film"))))
+    (should (seq-set-equal-p
+             '("--album=The Sounds of the Sounds of Science"
+               "--artist=Yo La Tengo"
+               "--name=Sea Urchins"
+               "--year=2020"
+               "--number=1"
+               "--composer=Ira Kaplan, Georgia Hubley, James Mcnew"
+               "--performer=Yo La Tengo"
+               "--album-number=1"
+               "--comment=new soundtrack to an old film"
+               "foo.flac")
+             (emms-tracktag--build-args track)))
+    (let ((track-with-empty-strings (copy-alist track)))
+      (setcdr (assq 'info-title track-with-empty-strings) "")
+      (setcdr (assq 'info-note track-with-empty-strings) "")
+      (should (seq-set-equal-p
+               '("--album=The Sounds of the Sounds of Science"
+                 "--artist=Yo La Tengo"
+                 "--year=2020"
+                 "--number=1"
+                 "--composer=Ira Kaplan, Georgia Hubley, James Mcnew"
+                 "--performer=Yo La Tengo"
+                 "--album-number=1"
+                 "--remove-comment"
+                 "--remove-name"
+                 "foo.flac")
+               (emms-tracktag--build-args track-with-empty-strings))))))
+
+;;; emms-tracktag-test.el ends here