MDL-70815 core_completion: Unit tests for activity_custom_completion

Tests cover
 - get_overall_completion_state()
 - is_available()
 - validate_rule()
Tests don't cover
 - methods that rely on static methods such as:
   - is_defined()
 - static methods in the class because they can't be mocked
 - abstract methods that can be tested better by the plugins
   that extend activity_custom_completion such as:
   - get_state()
   - get_defined_custom_rules()
   - get_custom_rule_descriptions()

completion/tests/activity_custom_completion_test.php

@@ -0,0 +1,187 @@
+<?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/>.
+
+declare(strict_types = 1);
+
+namespace core_completion;
+
+use advanced_testcase;
+use coding_exception;
+use moodle_exception;
+use PHPUnit\Framework\MockObject\MockObject;
+
+/**
+ * Class for unit testing core_completion/activity_custom_completion.
+ *
+ * @package   core_completion
+ * @copyright 2021 Jun Pataleta <jun@moodle.com>
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class activity_custom_completion_test extends advanced_testcase {
+
+    /**
+     * Fetches a mocked activity_custom_completion instance.
+     *
+     * @param string[] $methods List of methods to mock.
+     * @return activity_custom_completion|MockObject
+     */
+    protected function setup_mock(array $methods) {
+        return $this->getMockBuilder(activity_custom_completion::class)
+            ->disableOriginalConstructor()
+            ->onlyMethods($methods)
+            ->getMockForAbstractClass();
+    }
+
+    /**
+     * Data provider for test_get_overall_completion_state().
+     */
+    public function overall_completion_state_provider(): array {
+        global $CFG;
+        require_once($CFG->libdir . '/completionlib.php');
+        return [
+            'First incomplete, second complete' => [
+                ['completionsubmit', 'completioncreate'],
+                [COMPLETION_INCOMPLETE, COMPLETION_COMPLETE],
+                1,
+                COMPLETION_INCOMPLETE
+            ],
+            'First complete, second incomplete' => [
+                ['completionsubmit', 'completioncreate'],
+                [COMPLETION_COMPLETE, COMPLETION_INCOMPLETE],
+                2,
+                COMPLETION_INCOMPLETE
+            ],
+            'All complete' => [
+                ['completionsubmit', 'completioncreate'],
+                [COMPLETION_COMPLETE, COMPLETION_COMPLETE],
+                2,
+                COMPLETION_COMPLETE
+            ],
+            'No rules' => [
+                [],
+                [],
+                0,
+                COMPLETION_COMPLETE
+            ],
+        ];
+    }
+
+    /**
+     * Test for \core_completion\activity_custom_completion::get_overall_completion_state().
+     *
+     * @dataProvider overall_completion_state_provider
+     * @param string[] $rules The custom completion rules.
+     * @param int[] $rulestates The completion states of these custom completion rules.
+     * @param int $invokecount Expected invoke count of get_state().
+     * @param int $state The expected overall completion state
+     */
+    public function test_get_overall_completion_state(array $rules, array $rulestates, int $invokecount, int $state) {
+        $stub = $this->setup_mock([
+            'get_available_custom_rules',
+            'get_state',
+        ]);
+
+        // Mock activity_custom_completion's get_available_custom_rules() method.
+        $stub->expects($this->once())
+            ->method('get_available_custom_rules')
+            ->willReturn($rules);
+
+        // Mock activity_custom_completion's get_state() method.
+        if ($invokecount > 0) {
+            $stub->expects($this->exactly($invokecount))
+                ->method('get_state')
+                ->withConsecutive(
+                    [$rules[0]],
+                    [$rules[1]]
+                )
+                ->willReturn($rulestates[0], $rulestates[1]);
+        } else {
+            $stub->expects($this->never())
+                ->method('get_state');
+        }
+
+        $this->assertEquals($state, $stub->get_overall_completion_state());
+    }
+
+    /**
+     * Data provider for test_validate_rule().
+     *
+     * @return array[]
+     */
+    public function validate_rule_provider() {
+        return [
+            'Not defined' => [
+                false, true, coding_exception::class
+            ],
+            'Not available' => [
+                true, false, moodle_exception::class
+            ],
+            'Defined and available' => [
+                true, true, null
+            ],
+        ];
+    }
+
+    /**
+     * Test for validate_rule()
+     *
+     * @dataProvider validate_rule_provider
+     * @param bool $defined is_defined()'s mocked return value.
+     * @param bool $available is_available()'s mocked return value.
+     * @param string|null $expectedexception Expected expectation class name.
+     */
+    public function test_validate_rule(bool $defined, bool $available, ?string $expectedexception) {
+        $stub = $this->setup_mock([
+            'is_defined',
+            'is_available'
+        ]);
+
+        // Mock activity_custom_completion's is_defined() method.
+        $stub->expects($this->any())
+            ->method('is_defined')
+            ->willReturn($defined);
+
+        // Mock activity_custom_completion's is_available() method.
+        $stub->expects($this->any())
+            ->method('is_available')
+            ->willReturn($available);
+
+        if ($expectedexception) {
+            $this->expectException($expectedexception);
+        }
+        $stub->validate_rule('customcompletionrule');
+    }
+
+    /**
+     * Test for is_available().
+     */
+    public function test_is_available() {
+        $stub = $this->setup_mock([
+            'get_available_custom_rules',
+        ]);
+
+        // Mock activity_custom_completion's get_available_custom_rules() method.
+        $stub->expects($this->any())
+            ->method('get_available_custom_rules')
+            ->willReturn(['rule1', 'rule2']);
+
+        // Rule is available.
+        $this->assertTrue($stub->is_available('rule1'));
+
+        // Rule is not available.
+        $this->assertFalse($stub->is_available('rule'));
+    }
+}