emacs/test/lisp/emacs-lisp/syntax-tests.el

64 lines
2.2 KiB
EmacsLisp

;;; syntax-tests.el --- tests for syntax.el -*- lexical-binding: t; -*-
;; Copyright (C) 2020-2024 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/>.
;;; Code:
(require 'ert)
(require 'syntax)
(ert-deftest syntax-propertize--shift-groups-and-backrefs ()
"Test shifting of numbered groups and back-references in regexps."
;; A numbered group must be shifted.
(should
(string=
(syntax-propertize--shift-groups-and-backrefs
"\\(?2:[abc]+\\)foobar" 2)
"\\(?4:[abc]+\\)foobar"))
;; A back-reference \1 on a normal sub-regexp context must be
;; shifted.
(should
(string=
(syntax-propertize--shift-groups-and-backrefs "\\(a\\)\\1" 2)
"\\(a\\)\\3"))
;; Shifting must not happen if the \1 appears in a character class,
;; or in a \{\} repetition construct (although \1 isn't valid there
;; anyway).
(let ((rx-with-class "\\(a\\)[\\1-2]")
(rx-with-rep "\\(a\\)\\{1,\\1\\}"))
(should
(string=
(syntax-propertize--shift-groups-and-backrefs rx-with-class 2)
rx-with-class))
(should
(string=
(syntax-propertize--shift-groups-and-backrefs rx-with-rep 2)
rx-with-rep)))
;; Now numbered groups and back-references in combination.
(should
(string=
(syntax-propertize--shift-groups-and-backrefs
"\\(?2:[abc]+\\)foo\\(\\2\\)" 2)
"\\(?4:[abc]+\\)foo\\(\\4\\)"))
;; Emacs supports only the back-references \1,...,\9, so when a
;; shift would result in \10 or more, an error must be signaled.
(should-error
(syntax-propertize--shift-groups-and-backrefs "\\(a\\)\\3" 7)))
;;; syntax-tests.el ends here.