--- /dev/null
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle 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.
+//
+// Moodle 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 Moodle. If not, see <http://www.gnu.org/licenses/>.
+/**
+ * Provides the {@link filter_mathjaxloader_filtermath_testcase} class.
+ *
+ * @package filter_mathjaxloader
+ * @category test
+ * @copyright 2018 Markku Riekkinen
+ * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+defined('MOODLE_INTERNAL') || die();
+global $CFG;
+require_once($CFG->dirroot.'/filter/mathjaxloader/filter.php');
+/**
+ * Unit tests for the MathJax loader filter.
+ *
+ * @copyright 2018 Markku Riekkinen
+ * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class filter_mathjaxloader_filtermath_testcase extends advanced_testcase {
+
+ /**
+ * Test the functionality of {@link filter_mathjaxloader::filter()}.
+ *
+ * @param string $inputtext The text given by the user.
+ * @param string $expected The expected output after filtering.
+ *
+ * @dataProvider test_math_filtering_inputs
+ */
+ public function test_math_filtering($inputtext, $expected) {
+ $filter = new filter_mathjaxloader(context_system::instance(), []);
+ $this->assertEquals($expected, $filter->filter($inputtext));
+ }
+
+ /**
+ * Data provider for {@link self::test_math_filtering()}.
+ *
+ * @return array of [inputtext, expectedoutput] tuples.
+ */
+ public function test_math_filtering_inputs() {
+ return [
+ // One inline formula.
+ ['Some inline math \\( y = x^2 \\).',
+ '<span class="filter_mathjaxloader_equation">Some inline math <span class="nolink">\\( y = x^2 \\)</span>.</span>'],
+
+ // One inline and one display.
+ ['Some inline math \\( y = x^2 \\) and display formula \\[ S = \\sum_{n=1}^{\\infty} 2^n \\]',
+ '<span class="filter_mathjaxloader_equation">Some inline math <span class="nolink">\\( y = x^2 \\)</span> and '
+ . 'display formula <span class="nolink">\\[ S = \\sum_{n=1}^{\\infty} 2^n \\]</span></span>'],
+
+ // One display and one inline.
+ ['Display formula \\[ S = \\sum_{n=1}^{\\infty} 2^n \\] and some inline math \\( y = x^2 \\).',
+ '<span class="filter_mathjaxloader_equation">Display formula <span class="nolink">\\[ S = \\sum_{n=1}^{\\infty} 2^n \\]</span> and '
+ . 'some inline math <span class="nolink">\\( y = x^2 \\)</span>.</span>'],
+
+ // One inline and one display (with dollars).
+ ['Some inline math \\( y = x^2 \\) and display formula $$ S = \\sum_{n=1}^{\\infty} 2^n $$',
+ '<span class="filter_mathjaxloader_equation">Some inline math <span class="nolink">\\( y = x^2 \\)</span> and '
+ . 'display formula <span class="nolink">$$ S = \\sum_{n=1}^{\\infty} 2^n $$</span></span>'],
+
+ // One display (with dollars) and one inline.
+ ['Display formula $$ S = \\sum_{n=1}^{\\infty} 2^n $$ and some inline math \\( y = x^2 \\).',
+ '<span class="filter_mathjaxloader_equation">Display formula <span class="nolink">$$ S = \\sum_{n=1}^{\\infty} 2^n $$</span> and '
+ . 'some inline math <span class="nolink">\\( y = x^2 \\)</span>.</span>'],
+
+ // Inline math environment nested inside display environment (using a custom LaTex macro).
+ ['\\[ \\newcommand{\\False}{\\mathsf{F}} \\newcommand{\\NullF}{\\fbox{\\(\\False\\)}} \\] '
+ . 'Text with inline formula using the custom LaTex macro \\( a = \\NullF \\).',
+ '<span class="filter_mathjaxloader_equation"><span class="nolink">'
+ . '\\[ \\newcommand{\\False}{\\mathsf{F}} \\newcommand{\\NullF}{\\fbox{\\(\\False\\)}} \\]</span> '
+ . 'Text with inline formula using the custom LaTex macro <span class="nolink">\\( a = \\NullF \\)</span>.</span>'],
+
+ // Nested environments and some more content.
+ ['\\[ \\newcommand{\\False}{\\mathsf{F}} \\newcommand{\\NullF}{\\fbox{\\(\\False\\)}} \\] '
+ . 'Text with inline formula using the custom LaTex macro \\( a = \\NullF \\). Finally, a display formula '
+ . '$$ b = \\NullF $$',
+ '<span class="filter_mathjaxloader_equation"><span class="nolink">'
+ . '\\[ \\newcommand{\\False}{\\mathsf{F}} \\newcommand{\\NullF}{\\fbox{\\(\\False\\)}} \\]</span> '
+ . 'Text with inline formula using the custom LaTex macro <span class="nolink">\\( a = \\NullF \\)</span>. '
+ . 'Finally, a display formula <span class="nolink">$$ b = \\NullF $$</span></span>'],
+
+ // Broken math: the delimiters ($$) are not closed.
+ ['Writing text and starting display math. $$ k = i^3 \\newcommand{\\False}{\\mathsf{F}} \\newcommand{\\NullF}{\\fbox{\\(\\False\\)}} '
+ . 'More text and inline math \\( x = \\NullF \\).',
+ 'Writing text and starting display math. $$ k = i^3 \\newcommand{\\False}{\\mathsf{F}} \\newcommand{\\NullF}{\\fbox{\\(\\False\\)}} '
+ . 'More text and inline math \\( x = \\NullF \\).'],
+ ];
+ }
+}
