* test/automated/simple-test.el: Add test for bug#20698 (bug#21885)

(simple-test--transpositions): New macro.
(simple-transpose-subr): New test.

1 files changed, 17 insertions, 0 deletions

diff --git a/test/automated/simple-test.el b/test/automated/simple-test.el
index 86c9fc2e767..07b5eaa93e4 100644
--- a/test/automated/simple-test.el
+++ b/test/automated/simple-test.el
@@ -34,6 +34,17 @@
            (buffer-substring (point) (point-max)))))
 
 
+(defmacro simple-test--transpositions (&rest body)
+  (declare (indent 0)
+           (debug t))
+  `(with-temp-buffer
+     (emacs-lisp-mode)
+     (insert "(s1) (s2) (s3) (s4) (s5)")
+     (backward-sexp 1)
+     ,@body
+     (cons (buffer-substring (point-min) (point))
+           (buffer-substring (point) (point-max)))))
+
 
 ;;; `newline'
 (ert-deftest newline ()
@@ -233,6 +244,12 @@
      (car buffer-undo-list)
      (undo-auto--boundaries 'test))))
 
+;;; Transposition with negative args (bug#20698, bug#21885)
+(ert-deftest simple-transpose-subr ()
+  (should (equal (simple-test--transpositions (transpose-sexps -1))
+                 '("(s1) (s2) (s4)" . " (s3) (s5)")))
+  (should (equal (simple-test--transpositions (transpose-sexps -2))
+                 '("(s1) (s4)" . " (s2) (s3) (s5)"))))
 
 
 (provide 'simple-test)