1 files changed, 51 insertions, 0 deletions
diff --git a/test/lisp/progmodes/cperl-mode-tests.el b/test/lisp/progmodes/cperl-mode-tests.el
new file mode 100644
index 00000000000..be8b42d99a8
--- /dev/null
+++ b/test/lisp/progmodes/cperl-mode-tests.el
@@ -0,0 +1,51 @@
+;;; cperl-mode-tests --- Test for cperl-mode  -*- lexical-binding: t -*-
+
+;; Copyright (C) 2020 Free Software Foundation, Inc.
+
+;; Author: Harald Jörg <haj@posteo.de>
+;; Maintainer: Harald Jörg
+;; Keywords: internal
+;; Homepage: https://github.com/HaraldJoerg/cperl-mode
+
+;;; Commentary:
+
+;; This is a collection of tests for the fontification of CPerl-mode.
+
+;; Run these tests interactively:
+;; (ert-run-tests-interactively '(tag :fontification))
+
+;;; Code:
+
+(defvar cperl-test-mode #'cperl-mode)
+
+(defun cperl-test-ppss (text regexp)
+  "Return the `syntax-ppss' of the first character matched by REGEXP in TEXT."
+  (interactive)
+  (with-temp-buffer
+    (insert text)
+    (funcall cperl-test-mode)
+    (goto-char (point-min))
+    (re-search-forward regexp)
+    (syntax-ppss)))
+
+(ert-deftest cperl-mode-test-bug-42168 ()
+  "Verify that '/' is a division after ++ or --, not a regexp.
+Reported in https://github.com/jrockway/cperl-mode/issues/45.
+If seen as regular expression, then the slash is displayed using
+font-lock-constant-face.  If seen as a division, then it doesn't
+have a face property."
+  :tags '(:fontification)
+  ;; The next two Perl expressions have divisions.  Perl "punctuation"
+  ;; operators don't get a face.
+  (let ((code "{ $a++ / $b }"))
+    (should (equal (nth 8 (cperl-test-ppss code "/")) nil)))
+  (let ((code "{ $a-- / $b }"))
+    (should (equal (nth 8 (cperl-test-ppss code "/")) nil)))
+  ;; The next two Perl expressions have regular expressions.  The
+  ;; delimiter of a RE is fontified with font-lock-constant-face.
+  (let ((code "{ $a+ / $b } # /"))
+    (should (equal (nth 8 (cperl-test-ppss code "/")) 7)))
+  (let ((code "{ $a- / $b } # /"))
+    (should (equal (nth 8 (cperl-test-ppss code "/")) 7))))
+
+;;; cperl-mode-tests.el ends here