Use lexical-binding in elide-head.el and add tests

* lisp/elide-head.el: Use lexical-binding.
(elide-head-headers-to-hide): Remove redundant :group arg.
(elide-head-overlay): Use `defvar-local'.
(elide-head-show): Fix docstring.

* test/lisp/elide-head-tests.el: New file with tests for
elide-head.el.

1 files changed, 62 insertions, 0 deletions

diff --git a/test/lisp/elide-head-tests.el b/test/lisp/elide-head-tests.el
new file mode 100644
index 00000000000..c9ef26a8181
--- /dev/null
+++ b/test/lisp/elide-head-tests.el
@@ -0,0 +1,62 @@
+;;; elide-head-tests.el --- Tests for elide-head.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 'elide-head)
+(require 'ert)
+
+(ert-deftest elide-head-tests-elide-head ()
+  (let ((elide-head-headers-to-hide '(("START" . "END"))))
+    (with-temp-buffer
+      (insert "foo\nSTART\nHIDDEN\nEND\nbar")
+      (elide-head)
+      (let ((o (car (overlays-at 14))))
+        (should (= (overlay-start o) 10))
+        (should (= (overlay-end o) 21))
+        (should (overlay-get o 'invisible))
+        (should (overlay-get o 'evaporate))))))
+
+(ert-deftest elide-head-tests-elide-head-with-prefix-arg ()
+  (let ((elide-head-headers-to-hide '(("START" . "END"))))
+    (with-temp-buffer
+      (insert "foo\nSTART\nHIDDEN\nEND\nbar")
+      (elide-head)
+      (should (overlays-at 14))
+      (elide-head t)
+      (should-not (overlays-at 14)))))
+
+(ert-deftest elide-head-tests-show ()
+  (let ((elide-head-headers-to-hide '(("START" . "END"))))
+    (with-temp-buffer
+      (insert "foo\nSTART\nHIDDEN\nEND\nbar")
+      (elide-head)
+      (should (overlays-at 14))
+      (elide-head-show)
+      (should-not (overlays-at 14)))))
+
+(provide 'elide-head-tests)
+;;; elide-head-tests.el ends here