--- /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/>.
+
+/**
+ * Unit tests for lib/outputcomponents.php.
+ *
+ * @package core
+ * @category test
+ * @copyright 2011 David Mudrak <david@moodle.com>
+ * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+namespace core\output;
+
+use advanced_testcase;
+use coding_exception;
+
+/**
+ * Unit tests for the `icon_system` class.
+ *
+ * @coversDefaultClass core\output\icon_system
+ */
+class icon_system_test extends advanced_testcase {
+ /**
+ * Check whether the supplied classes are valid icon subsystems of the supplied one.
+ *
+ * @covers ::is_valid_system
+ * @dataProvider is_valid_subsystem_provider
+ * @param string $parent The class to call ::is_valid_system() on
+ * @param string $system The class to request
+ * @param bool $expected Whether the supplied relationship is valid
+ */
+ public function test_is_valid_subsystem(string $parent, string $system, bool $expected): void {
+ $this->assertEquals($expected, $parent::is_valid_system($system));
+ }
+
+ /**
+ * Ensure that the ::instance() function throws an appropriate Exception when an inappropriate relationship is
+ * specified.
+ *
+ * @covers ::instance
+ * @dataProvider invalid_instance_provider
+ * @param string $parent The class to call ::instance() on
+ * @param string $system The class to request
+ */
+ public function test_invalid_instance(string $parent, string $system): void {
+ $this->expectException(coding_exception::class);
+ $this->expectExceptionMessage("Invalid icon system requested '{$system}'");
+
+ $parent::instance($system);
+ }
+
+ /**
+ * Ensure that the ::instance() function returns an instance of the supplied system for a valid icon system
+ * relationship.
+ *
+ * @covers ::instance
+ * @dataProvider valid_instance_provider
+ * @param string $parent The class to call ::instance() on
+ * @param string $system The class to request
+ */
+ public function test_valid_instance(string $parent, string $system): void {
+ $instance = $parent::instance($system);
+ $this->assertInstanceOf($parent, $instance);
+ $this->assertInstanceOf($system, $instance);
+ }
+
+ /**
+ * Ensure that subsequent calls without arguments to ::instance() return the exact same instance.
+ *
+ * @covers ::instance
+ */
+ public function test_instance_singleton(): void {
+ $singleton = icon_system::instance();
+
+ // Calling instance() again returns the same singleton.
+ $this->assertSame($singleton, icon_system::instance());
+ }
+
+ /**
+ * Ensure thaat subsequent calls with an argument to ::instance() return the exact same instance.
+ *
+ * @covers ::instance
+ */
+ public function test_instance_singleton_named_default(): void {
+ global $PAGE;
+ $singleton = icon_system::instance();
+
+ $defaultsystem = $PAGE->theme->get_icon_system();
+ $this->assertSame($singleton, icon_system::instance($defaultsystem));
+ }
+
+ /**
+ * Ensure that ::instance() returns an instance of the correct icon system when requested on the core icon_system
+ * class.
+ *
+ * @covers ::instance
+ * @dataProvider valid_instance_provider
+ * @param string $parent The class to call ::instance() on
+ * @param string $child The class to request
+ */
+ public function test_instance_singleton_named(string $parent, string $child): void {
+ $iconsystem = icon_system::instance($child);
+ $this->assertInstanceOf($child, $iconsystem);
+ }
+
+ /**
+ * Ensure that ::instance() returns an instance of the correct icon system when called on a named parent class.
+ *
+ * @covers ::instance
+ * @dataProvider valid_instance_provider
+ * @param string $parent The class to call ::instance() on
+ * @param string $child The class to request
+ */
+ public function test_instance_singleton_named_child(string $parent, string $child): void {
+ $iconsystem = $parent::instance($child);
+ $this->assertInstanceOf($parent, $iconsystem);
+ $this->assertInstanceOf($child, $iconsystem);
+ }
+
+ /**
+ * Ensure that the ::reset_caches() function resets the stored instance such that ::instance() returns a new
+ * instance in subsequent calls.
+ *
+ * @covers ::instance
+ * @covers ::reset_caches
+ */
+ public function test_instance_singleton_reset(): void {
+ $singleton = icon_system::instance();
+
+ // Reset the cache.
+ icon_system::reset_caches();
+
+ // Calling instance() again returns a new singleton.
+ $newsingleton = icon_system::instance();
+ $this->assertNotSame($singleton, $newsingleton);
+
+ // Calling it again gets the new singleton.
+ $this->assertSame($newsingleton, icon_system::instance());
+ }
+
+ /**
+ * Returns data for data providers containing:
+ * - parent icon system
+ * - child icon system
+ * - whether it is a valid child
+ *
+ * @return array
+ */
+ public function icon_system_provider(): array {
+ return [
+ 'icon_system => icon_system_standard' => [
+ icon_system::class,
+ icon_system_standard::class,
+ true,
+ ],
+ 'icon_system => icon_system_fontawesome' => [
+ icon_system::class,
+ icon_system_fontawesome::class,
+ true,
+ ],
+ 'icon_system => \theme_classic\output\icon_system_fontawesome' => [
+ icon_system::class,
+ \theme_classic\output\icon_system_fontawesome::class,
+ true,
+ ],
+ 'icon_system => notification' => [
+ icon_system::class,
+ notification::class,
+ false,
+ ],
+
+ 'icon_system_standard => icon_system_standard' => [
+ icon_system_standard::class,
+ icon_system_standard::class,
+ true,
+ ],
+ 'icon_system_standard => icon_system_fontawesome' => [
+ icon_system_standard::class,
+ icon_system_fontawesome::class,
+ false,
+ ],
+ 'icon_system_standard => \theme_classic\output\icon_system_fontawesome' => [
+ icon_system_standard::class,
+ \theme_classic\output\icon_system_fontawesome::class,
+ false,
+ ],
+ 'icon_system_fontawesome => icon_system_standard' => [
+ icon_system_fontawesome::class,
+ icon_system_standard::class,
+ false,
+ ],
+ ];
+ }
+
+ /**
+ * Data provider for tests of `is_valid`.
+ *
+ * @return array
+ */
+ public function is_valid_subsystem_provider(): array {
+ return $this->icon_system_provider();
+ }
+
+ /**
+ * Data provider for tests of `instance` containing only invalid tests.
+ *
+ * @return array
+ */
+ public function invalid_instance_provider(): array {
+ return array_filter(
+ $this->icon_system_provider(),
+ function($data) {
+ return !$data[2];
+ },
+ ARRAY_FILTER_USE_BOTH
+ );
+ }
+
+ /**
+ * Data provider for tests of `instance` containing only valid tests.
+ *
+ * @return array
+ */
+ public function valid_instance_provider(): array {
+ return array_filter(
+ $this->icon_system_provider(),
+ function($data) {
+ return $data[2];
+ },
+ ARRAY_FILTER_USE_BOTH
+ );
+ }
+
+}
