Run admin/cus-tests.el tests from test suite

* test/Makefile.in (SUBDIRS): Run tests in new directory "misc",
intended for tests not belonging to any one file.
* test/misc/test-custom-deps.el:
* test/misc/test-custom-libs.el:
* test/misc/test-custom-noloads.el:
* test/misc/test-custom-opts.el: New files.
* test/lisp/custom-tests.el (custom--test-local-option): Move test to
above new file test-custom-opts.el.

* admin/cus-test.el: Document running tests from regular test suite.
* test/file-organization.org (Test Files): Document new test directory
"misc" for tests not belonging to any one file.

1 files changed, 39 insertions, 0 deletions

diff --git a/test/misc/test-custom-opts.el b/test/misc/test-custom-opts.el
new file mode 100644
index 00000000000..fa6b9e66aef
--- /dev/null
+++ b/test/misc/test-custom-opts.el
@@ -0,0 +1,39 @@
+;;; test-custom-opts.el --- Test custom opts  -*- 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 GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; The command `cus-test-opts' tests many (all?) custom options.
+
+;;; Code:
+
+(require 'ert)
+
+(defconst custom-test-admin-cus-test
+  (expand-file-name "admin/cus-test.el" source-directory))
+
+(declare-function cus-test-opts custom-test-admin-cus-test)
+
+(ert-deftest check-for-wrong-custom-opts ()
+  :tags '(:expensive-test)
+  (skip-unless (file-readable-p custom-test-admin-cus-test))
+  (load custom-test-admin-cus-test)
+  (should (null (cus-test-opts t))))
+
+;;; test-custom-opts.el ends here