;;; misc-tests.el --- Tests for misc.el  -*- lexical-binding:t -*-

;; Copyright (C) 2020-2025 Free Software Foundation, Inc.

;; Author: Stefan Kangas <stefankangas@gmail.com>

;; 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 'misc)

(defmacro with-misc-test (original result &rest body)
  (declare (indent 2))
  `(with-temp-buffer
     (insert ,original)
     ,@body
     (should (equal (buffer-string) ,result))))

(ert-deftest misc-test-copy-from-above-command ()
  (with-misc-test "abc\n" "abc\nabc"
    (copy-from-above-command))
  (with-misc-test "abc\n" "abc\nab"
    (copy-from-above-command 2)))

(ert-deftest misc-test-zap-up-to-char ()
  (with-misc-test "abcde" "cde"
    (goto-char (point-min))
    (zap-up-to-char 1 ?c))
  (with-misc-test "abcde abc123" "c123"
    (goto-char (point-min))
    (zap-up-to-char 2 ?c))
  (let ((case-fold-search t))
    (with-misc-test "abcdeCXYZ" "cdeCXYZ"
      (goto-char (point-min))
      (zap-up-to-char 1 ?C))
    (with-misc-test "abcdeCXYZ" "CXYZ"
      (goto-char (point-min))
      (zap-up-to-char 1 ?C 'interactive))))

(ert-deftest misc-test-upcase-char ()
  (with-misc-test "abcde" "aBCDe"
    (goto-char (1+ (point-min)))
    (upcase-char 3)))

(ert-deftest misc-test-forward-to-word ()
  (with-temp-buffer
    (insert "    -   abc")
    (goto-char (point-min))
    (forward-to-word 1)
    (should (equal (point) 9)))
  (with-temp-buffer
    (insert "a b c")
    (goto-char (point-min))
    (forward-to-word 3)
    (should (equal (point) 6))))

(ert-deftest misc-test-backward-to-word ()
  (with-temp-buffer
    (insert "abc    -   ")
    (backward-to-word 1)
    (should (equal (point) 4)))
  (with-temp-buffer
    (insert "a b c")
    (backward-to-word 3)
    (should (equal (point) 1))))

(ert-deftest misc--duplicate-line ()
  ;; Duplicate a line (twice).
  (with-temp-buffer
    (insert "abc\ndefg\nh\n")
    (goto-char 7)
    (duplicate-line 2)
    (should (equal (buffer-string) "abc\ndefg\ndefg\ndefg\nh\n"))
    (should (equal (point) 7)))
  ;; Duplicate a line (twice) and move point to the first duplicated line.
  (with-temp-buffer
    (insert "abc\ndefg\nh\n")
    (goto-char 7)
    (let ((duplicate-line-final-position 1)) (duplicate-line 2))
    (should (equal (buffer-string) "abc\ndefg\ndefg\ndefg\nh\n"))
    (should (equal (point) 12)))
  ;; Duplicate a line (twice) and move point to the last duplicated line.
  (with-temp-buffer
    (insert "abc\ndefg\nh\n")
    (goto-char 7)
    (let ((duplicate-line-final-position -1)) (duplicate-line 2))
    (should (equal (buffer-string) "abc\ndefg\ndefg\ndefg\nh\n"))
    (should (equal (point) 17)))
  ;; Duplicate a non-terminated line.
  (with-temp-buffer
    (insert "abc")
    (goto-char 2)
    (duplicate-line)
    (should (equal (buffer-string) "abc\nabc\n"))
    (should (equal (point) 2))))

(require 'rect)

(ert-deftest misc--duplicate-dwim ()
  (let ((duplicate-line-final-position 0)
        (duplicate-region-final-position 0))
    ;; Duplicate a line.
    (dolist (final-pos '(0 -1 1))
      (ert-info ((prin1-to-string final-pos) :prefix "final-pos: ")
        (with-temp-buffer
          (insert "abc\ndefg\nh\n")
          (goto-char 7)
          (let ((duplicate-line-final-position final-pos))
            (duplicate-dwim 3))
          (should (equal (buffer-string) "abc\ndefg\ndefg\ndefg\ndefg\nh\n"))
          (let ((delta (* 5 (if (< final-pos 0) 3 final-pos))))
            (should (equal (point) (+ 7 delta)))))))

    ;; Duplicate a region.
    (dolist (final-pos '(0 -1 1))
      (ert-info ((prin1-to-string final-pos) :prefix "final-pos: ")
        (with-temp-buffer
          (insert "abCDEFghi")
          (set-mark 3)
          (goto-char 7)
          (transient-mark-mode)
          (should (use-region-p))
          (let ((duplicate-region-final-position final-pos))
            (duplicate-dwim 3))
          (should (equal (buffer-string) "abCDEFCDEFCDEFCDEFghi"))
          (should (region-active-p))
          (let ((delta (* 4 (if (< final-pos 0) 3 final-pos))))
            (should (equal (point) (+ 7 delta)))
            (should (equal (mark) (+ 3 delta)))))))

    ;; Duplicate a rectangular region (sparse).
    (with-temp-buffer
      (insert "x\n>a\n>bcde\n>fg\nyz\n")
      (goto-char 4)
      (rectangle-mark-mode)
      (goto-char 15)
      (rectangle-forward-char 1)
      (duplicate-dwim)
      (should (equal (buffer-string) "x\n>a  a  \n>bcdbcde\n>fg fg \nyz\n"))
      (should (equal (point) 24))
      (should (region-active-p))
      (should rectangle-mark-mode)
      (should (equal (mark) 4)))

    ;; Idem (dense).
    (dolist (final-pos '(0 -1 1))
      (ert-info ((prin1-to-string final-pos) :prefix "final-pos: ")
        (with-temp-buffer
          (insert "aBCd\neFGh\niJKl\n")
          (goto-char 2)
          (rectangle-mark-mode)
          (goto-char 14)
          (let ((duplicate-region-final-position final-pos))
            (duplicate-dwim 3))
          (should (equal (buffer-string)
                         "aBCBCBCBCd\neFGFGFGFGh\niJKJKJKJKl\n"))
          (should (region-active-p))
          (should rectangle-mark-mode)
          (let ((hdelta (* 2 (if (< final-pos 0) 3 final-pos)))
                (vdelta 12))
            (should (equal (point) (+ 14 vdelta hdelta)))
            (should (equal (mark) (+ 2 hdelta)))))))))

;; Check that `string-pixel-width' returns a consistent result in the
;; various situations that can lead to erroneous results.
(ert-deftest misc-test-string-pixel-width-char-property-alias-alist ()
  "Test `string-pixel-width' with `char-property-alias-alist'."
  (with-temp-buffer
    (let ((text0 (propertize "This text"
                             'display "xxxx"
                             'face 'variable-pitch))
          (text1 (propertize "This text"
                             'my-display "xxxx"
                             'my-face 'variable-pitch)))
      (setq-local char-property-alias-alist '((display my-display)
                                              (face my-face)))
      (should (= (string-pixel-width text0 (current-buffer))
                 (string-pixel-width text1 (current-buffer)))))))

;; This test never fails in batch mode.
(ert-deftest misc-test-string-pixel-width-face-remapping-alist ()
  "Test `string-pixel-width' with `face-remapping-alist'."
  (with-temp-buffer
    (setq-local face-remapping-alist '((variable-pitch . default)))
    (let ((text0 (propertize "This text" 'face 'default))
          (text1 (propertize "This text" 'face 'variable-pitch)))
      (should (= (string-pixel-width text0 (current-buffer))
                 (string-pixel-width text1 (current-buffer)))))))

(ert-deftest misc-test-string-pixel-width-default-text-properties ()
  "Test `string-pixel-width' with `default-text-properties'."
  (with-temp-buffer
    (setq-local default-text-properties '(display "XXXX"))
    (let ((text0 (propertize "This text" 'display "XXXX"))
          (text1 "This text"))
      (should (= (string-pixel-width text0 (current-buffer))
                 (string-pixel-width text1 (current-buffer)))))))

(ert-deftest misc-test-string-pixel-width-line-and-wrap-prefix ()
  "Test `string-pixel-width' with `line-prefix' and `wrap-prefix'."
  (let ((lp (default-value 'line-prefix))
        (wp (default-value 'line-prefix))
        (text (make-string 2000 ?X))
        w0 w1)
    (unwind-protect
        (progn
          (setq-default line-prefix nil wrap-prefix nil)
          (setq w0 (string-pixel-width text))
          (setq-default line-prefix "PPPP" wrap-prefix "WWWW")
          (setq w1 (string-pixel-width text)))
      (setq-default line-prefix lp wrap-prefix wp))
    (should (= w0 w1))))

;; This test never fails in batch mode.
(ert-deftest misc-test-string-pixel-width-display-line-numbers ()
  "Test `string-pixel-width' with `display-line-numbers'."
  (let ((dln (default-value 'display-line-numbers))
        (text "This text")
        w0 w1)
    (unwind-protect
        (progn
          (setq-default display-line-numbers nil)
          (setq w0 (string-pixel-width text))
          (setq-default display-line-numbers t)
          (setq w1 (string-pixel-width text)))
      (setq-default display-line-numbers dln))
    (should (= w0 w1))))

(provide 'misc-tests)
;;; misc-tests.el ends here