Hide obsolete options in most customize commands

* lisp/cus-edit.el (custom--filter-obsolete-variables): New defun.
* lisp/cus-edit.el (customize-changed-options)
(customize-apropos, custom-group-value-create): Hide obsolete user
options.  (Bug#44598)
* test/lisp/cus-edit-tests.el: New file.

1 files changed, 80 insertions, 0 deletions

diff --git a/test/lisp/cus-edit-tests.el b/test/lisp/cus-edit-tests.el
new file mode 100644
index 00000000000..4d148b4f411
--- /dev/null
+++ b/test/lisp/cus-edit-tests.el
@@ -0,0 +1,80 @@
+;;; cus-edit-tests.el --- Tests for cus-edit.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 'ert-x)
+(require 'cus-edit)
+
+(defmacro with-cus-edit-test (buffer &rest body)
+  (declare (indent 1))
+  `(save-window-excursion
+     (unwind-protect
+         (progn ,@body)
+       (when-let ((buf (get-buffer ,buffer)))
+         (kill-buffer buf)))))
+
+
+;;;; showing/hiding obsolete options
+
+(defgroup cus-edit-tests nil "test"
+  :group 'test-group)
+
+(defcustom cus-edit-tests--obsolete-option-tag nil
+  "This should never be removed; it is obsolete for testing purposes."
+  :type 'boolean
+  :version "917.10") ; a super high version number
+(make-obsolete-variable 'cus-edit-tests--obsolete-option-tag nil "X.X-test")
+(defconst cus-edit-tests--obsolete-option-tag
+  (custom-unlispify-tag-name 'cus-edit-tests--obsolete-option-tag))
+
+(ert-deftest cus-edit-tests-customize-apropos/hide-obsolete ()
+  (with-cus-edit-test "*Customize Apropos*"
+    (customize-apropos "cus-edit-tests")
+    (should-not (search-forward cus-edit-tests--obsolete-option-tag nil t))))
+
+(ert-deftest cus-edit-tests-customize-changed-options/hide-obsolete ()
+  (with-cus-edit-test "*Customize Changed Options*"
+    (customize-changed-options "917.2") ; some future version
+    (should-not (search-forward cus-edit-tests--obsolete-option-tag nil t))))
+
+(ert-deftest cus-edit-tests-customize-group/hide-obsolete ()
+  "Check that obsolete variables do not show up."
+  (with-cus-edit-test "*Customize Group: Cus Edit Tests*"
+    (customize-group 'cus-edit-tests)
+    (should-not (search-forward cus-edit-tests--obsolete-option-tag nil t))))
+
+(ert-deftest cus-edit-tests-customize-option/show-obsolete ()
+  (with-cus-edit-test "*Customize Option: Cus Edit Tests Obsolete Option Tag*"
+    (customize-option 'cus-edit-tests--obsolete-option-tag)
+    (goto-char (point-min))
+    (should (search-forward cus-edit-tests--obsolete-option-tag nil t))))
+
+(ert-deftest cus-edit-tests-customize-saved/show-obsolete ()
+  ;; FIXME: How to test for saved options?
+  :expected-result :failed
+  (with-cus-edit-test "*Customize Saved*"
+    (customize-saved)
+    (should (search-forward cus-edit-tests--obsolete-option-tag nil t))))
+
+(provide 'cus-edit-tests)
+;;; cus-edit-tests.el ends here