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

;; Copyright (C) 2019 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 'page)

(defvar page-tests-page-1 "Page 1/3"
  "Example text used to test page.el.")
(defvar page-tests-page-2 "\nPage 2/3"
  "Example text used to test page.el.")
(defvar page-tests-page-3 "\nPage 3/3\nLast line"
  "Example text used to test page.el.")
(defvar page-tests-break "\n"
  "Page break used to test page.el.")
(defvar page-tests-example-text
  (concat page-tests-page-1 page-tests-break
          page-tests-page-2 page-tests-break
          page-tests-page-3)
  "Example text used to test page.el.")

(ert-deftest page-tests-forward-page ()
  (with-temp-buffer
    (insert page-tests-example-text)
    (goto-char (point-min))
    (forward-page)
    (should (looking-at page-tests-page-2))
    (forward-page)
    (should (looking-at page-tests-page-3))
    (forward-page)
    (should (equal (point) (point-max)))))

(ert-deftest page-tests-backward-page ()
  (with-temp-buffer
    (insert page-tests-example-text)
    (goto-char (point-max))
    (backward-page)
    (should (looking-at page-tests-page-3))
    (backward-page)
    (should (looking-at page-tests-page-2))
    (backward-page)
    (should (looking-at page-tests-page-1))
    (should (equal (point) (point-min)))))

(ert-deftest page-tests-mark-page ()
  (with-temp-buffer
    (insert page-tests-example-text)
    (goto-char (point-min))
    (mark-page)
    (should (looking-at page-tests-page-1))
    (should mark-active)
    (should (equal (mark) 11))))

(ert-deftest page-tests-narrow-to-page ()
  (with-temp-buffer
    (insert page-tests-example-text)
    (goto-char (point-min))
    (narrow-to-page)
    (should (equal (buffer-string)
                   (concat page-tests-page-1 "\n")))))

(ert-deftest page-tests-count-lines-page ()
  (with-temp-buffer
    (insert page-tests-example-text)
    (goto-char (point-min))
    (should (equal (count-lines-page) "Page has 1 lines (0 + 1)"))
    (goto-char (point-max))
    (should (equal (count-lines-page) "Page has 3 lines (3 + 0)"))))

(ert-deftest page-tests-what-page ()
  (with-temp-buffer
    (insert page-tests-example-text)
    (goto-char (point-min))
    (should (equal (what-page) "Page 1, line 1"))
    (forward-page)
    (should (equal (what-page) "Page 2, line 2"))
    (forward-page)
    (should (equal (what-page) "Page 3, line 4"))))

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