Proyectos de Subversion Moodle

<?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/>.

namespace core_question;

use core_question\local\bank\condition;

use core_question\local\bank\question_version_status;

use core_question\local\bank\random_question_loader;

use core_question_generator;

use mod_quiz\quiz_settings;

use qubaid_list;

use question_bank;

use question_engine;

use question_filter_test_helper;

defined('MOODLE_INTERNAL') || die();

global $CFG;

require_once($CFG->dirroot . '/question/engine/tests/helpers.php');

require_once($CFG->dirroot . '/mod/quiz/tests/quiz_question_helper_test_trait.php');

/**

 * Tests for the {@see \core_question\local\bank\random_question_loader} class.

 *

 * @package   core_question

 * @copyright 2015 The Open University

 * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 * @covers    \random_question_loader

 */

final class random_question_loader_test extends \advanced_testcase {

    use \quiz_question_helper_test_trait;

    public function test_empty_category_gives_null(): void {

        $this->resetAfterTest();

        $generator = $this->getDataGenerator()->get_plugin_generator('core_question');

        $cat = $generator->create_question_category();

        $loader = new random_question_loader(new qubaid_list([]));

        $filters = question_filter_test_helper::create_filters([$cat->id]);

        $this->assertNull($loader->get_next_filtered_question_id($filters));

        $filters = question_filter_test_helper::create_filters([$cat->id], 1);

        $this->assertNull($loader->get_next_filtered_question_id($filters));

    }

    public function test_unknown_category_behaves_like_empty(): void {

        // It is up the caller to make sure the category id is valid.

        $loader = new random_question_loader(new qubaid_list([]));

        $filters = question_filter_test_helper::create_filters([-1], 1);

        $this->assertNull($loader->get_next_filtered_question_id($filters));

    }

    public function test_descriptions_not_returned(): void {

        $this->resetAfterTest();

        $generator = $this->getDataGenerator()->get_plugin_generator('core_question');

        $cat = $generator->create_question_category();

        $info = $generator->create_question('description', null, ['category' => $cat->id]);

        $loader = new random_question_loader(new qubaid_list([]));

        $filters = question_filter_test_helper::create_filters([$cat->id]);

        $this->assertNull($loader->get_next_filtered_question_id($filters));

    }

    public function test_hidden_questions_not_returned(): void {

        global $DB;

        $this->resetAfterTest();

        $generator = $this->getDataGenerator()->get_plugin_generator('core_question');

        $cat = $generator->create_question_category();

        $question1 = $generator->create_question('shortanswer', null, ['category' => $cat->id]);

        $DB->set_field('question_versions', 'status',

                \core_question\local\bank\question_version_status::QUESTION_STATUS_HIDDEN, ['questionid' => $question1->id]);

        $loader = new random_question_loader(new qubaid_list([]));

        $filters = question_filter_test_helper::create_filters([$cat->id]);

        $this->assertNull($loader->get_next_filtered_question_id($filters));

    }

    public function test_cloze_subquestions_not_returned(): void {

        $this->resetAfterTest();

        $generator = $this->getDataGenerator()->get_plugin_generator('core_question');

        $cat = $generator->create_question_category();

        $question1 = $generator->create_question('multianswer', null, ['category' => $cat->id]);

        $loader = new random_question_loader(new qubaid_list([]));

        $filters = question_filter_test_helper::create_filters([$cat->id]);

        $this->assertEquals($question1->id, $loader->get_next_filtered_question_id($filters));

        $this->assertNull($loader->get_next_filtered_question_id($filters));

    }

    public function test_random_questions_not_returned(): void {

        $this->resetAfterTest();

        $this->setAdminUser();

        $generator = $this->getDataGenerator()->get_plugin_generator('core_question');

        $cat = $generator->create_question_category();

        $course = $this->getDataGenerator()->create_course();

        $quiz = $this->getDataGenerator()->create_module('quiz', ['course' => $course]);

        $this->add_random_questions($quiz->id, 1, $cat->id, 1);

        $loader = new random_question_loader(new qubaid_list([]));

        $filters = question_filter_test_helper::create_filters([$cat->id]);

        $this->assertNull($loader->get_next_filtered_question_id($filters));

    }

    public function test_draft_questions_not_returned(): void {

        $this->resetAfterTest();

        $this->setAdminUser();

        /** @var core_question_generator $questiongenerator */

        $questiongenerator = $this->getDataGenerator()->get_plugin_generator('core_question');

        // Create a question in draft state.

        $category = $questiongenerator->create_question_category();

        $questiongenerator->create_question('shortanswer', null,

                ['category' => $category->id, 'status' => question_version_status::QUESTION_STATUS_DRAFT]);

        // Try to a random question from that category - should not be one.

        $filtercondition = [

            'category' => [

                'jointype' => condition::JOINTYPE_DEFAULT,

                'values' => [$category->id],

                'filteroptions' => ['includesubcategories' => false],

            ],

        ];

        $loader = new random_question_loader(new qubaid_list([]));

        $this->assertNull($loader->get_next_filtered_question_id($filtercondition));

    }

    public function test_questions_with_later_draft_version_is_returned(): void {

        $this->resetAfterTest();

        $this->setAdminUser();

        /** @var core_question_generator $questiongenerator */

        $questiongenerator = $this->getDataGenerator()->get_plugin_generator('core_question');

        // Create a question in draft state.

        $category = $questiongenerator->create_question_category();

        $question = $questiongenerator->create_question('shortanswer', null,

                ['questiontext' => 'V1', 'category' => $category->id]);

        $questiongenerator->update_question($question, null,

                ['questiontext' => 'V2', 'status' => question_version_status::QUESTION_STATUS_DRAFT]);

        // Try to a random question from that category - should get V1.

        $filtercondition = [

            'category' => [

                'jointype' => condition::JOINTYPE_DEFAULT,

                'values' => [$category->id],

                'filteroptions' => ['includesubcategories' => false],

            ],

        ];

        $loader = new random_question_loader(new qubaid_list([]));

        $this->assertEquals($question->id, $loader->get_next_filtered_question_id($filtercondition));

    }

    public function test_one_question_category_returns_that_q_then_null(): void {

        $this->resetAfterTest();

        $generator = $this->getDataGenerator()->get_plugin_generator('core_question');

        $cat = $generator->create_question_category();

        $question1 = $generator->create_question('shortanswer', null, ['category' => $cat->id]);

        $loader = new random_question_loader(new qubaid_list([]));

        $filters = question_filter_test_helper::create_filters([$cat->id], 1);

        $this->assertEquals($question1->id, $loader->get_next_filtered_question_id($filters));

        $filters = question_filter_test_helper::create_filters([$cat->id]);

        $this->assertNull($loader->get_next_filtered_question_id($filters));

    }

    public function test_two_question_category_returns_both_then_null(): void {

        $this->resetAfterTest();

        $generator = $this->getDataGenerator()->get_plugin_generator('core_question');

        $cat = $generator->create_question_category();

        $question1 = $generator->create_question('shortanswer', null, ['category' => $cat->id]);

        $question2 = $generator->create_question('shortanswer', null, ['category' => $cat->id]);

        $loader = new random_question_loader(new qubaid_list([]));

        $questionids = [];

        $filters = question_filter_test_helper::create_filters([$cat->id]);

        $questionids[] = $loader->get_next_filtered_question_id($filters);

        $questionids[] = $loader->get_next_filtered_question_id($filters);

        sort($questionids);

        $this->assertEquals([$question1->id, $question2->id], $questionids);

        $filters = question_filter_test_helper::create_filters([$cat->id], 1);

        $this->assertNull($loader->get_next_filtered_question_id($filters));

    }

    public function test_nested_categories(): void {

        $this->resetAfterTest();

        $generator = $this->getDataGenerator()->get_plugin_generator('core_question');

        $cat1 = $generator->create_question_category();

        $cat2 = $generator->create_question_category(['parent' => $cat1->id]);

        $question1 = $generator->create_question('shortanswer', null, ['category' => $cat1->id]);

        $question2 = $generator->create_question('shortanswer', null, ['category' => $cat2->id]);

        $loader = new random_question_loader(new qubaid_list([]));

        $filters = question_filter_test_helper::create_filters([$cat2->id], 1);

        $this->assertEquals($question2->id, $loader->get_next_filtered_question_id($filters));

        $filters = question_filter_test_helper::create_filters([$cat1->id], 1);

        $this->assertEquals($question1->id, $loader->get_next_filtered_question_id($filters));

        $filters = question_filter_test_helper::create_filters([$cat1->id]);

        $this->assertNull($loader->get_next_filtered_question_id($filters));

    }

    public function test_used_question_not_returned_until_later(): void {

        $this->resetAfterTest();

        $generator = $this->getDataGenerator()->get_plugin_generator('core_question');

        $cat = $generator->create_question_category();

        $question1 = $generator->create_question('shortanswer', null, ['category' => $cat->id]);

        $question2 = $generator->create_question('shortanswer', null, ['category' => $cat->id]);

        $loader = new random_question_loader(new qubaid_list([]),

                [$question2->id => 2]);

        $filters = question_filter_test_helper::create_filters([$cat->id]);

        $this->assertEquals($question1->id, $loader->get_next_filtered_question_id($filters));

        $this->assertNull($loader->get_next_filtered_question_id($filters));

    }

    public function test_previously_used_question_not_returned_until_later(): void {

        $this->resetAfterTest();

        $generator = $this->getDataGenerator()->get_plugin_generator('core_question');

        $cat = $generator->create_question_category();

        $question1 = $generator->create_question('shortanswer', null, ['category' => $cat->id]);

        $question2 = $generator->create_question('shortanswer', null, ['category' => $cat->id]);

        $quba = question_engine::make_questions_usage_by_activity('test', \context_system::instance());

        $quba->set_preferred_behaviour('deferredfeedback');

        $question = question_bank::load_question($question2->id);

        $quba->add_question($question);

        $quba->add_question($question);

        $quba->start_all_questions();

        question_engine::save_questions_usage_by_activity($quba);

        $loader = new random_question_loader(new qubaid_list([$quba->get_id()]));

        $filters = question_filter_test_helper::create_filters([$cat->id]);

        $this->assertEquals($question1->id, $loader->get_next_filtered_question_id($filters));

        $this->assertEquals($question2->id, $loader->get_next_filtered_question_id($filters));

        $this->assertNull($loader->get_next_filtered_question_id($filters));

    }

    public function test_empty_category_does_not_have_question_available(): void {

        $this->resetAfterTest();

        $generator = $this->getDataGenerator()->get_plugin_generator('core_question');

        $cat = $generator->create_question_category();

        $loader = new random_question_loader(new qubaid_list([]));

        $filters = question_filter_test_helper::create_filters([$cat->id]);

        $this->assertFalse($loader->is_filtered_question_available($filters, 1));

        $filters = question_filter_test_helper::create_filters([$cat->id], 1);

        $this->assertFalse($loader->is_filtered_question_available($filters, 1));

    }

    public function test_descriptions_not_available(): void {

        $this->resetAfterTest();

        $generator = $this->getDataGenerator()->get_plugin_generator('core_question');

        $cat = $generator->create_question_category();

        $info = $generator->create_question('description', null, ['category' => $cat->id]);

        $loader = new random_question_loader(new qubaid_list([]));

        $filters = question_filter_test_helper::create_filters([$cat->id]);

        $this->assertFalse($loader->is_filtered_question_available($filters, $info->id));

        $filters = question_filter_test_helper::create_filters([$cat->id], 1);

        $this->assertFalse($loader->is_filtered_question_available($filters, $info->id));

    }

    public function test_existing_question_is_available_but_then_marked_used(): void {

        $this->resetAfterTest();

        $generator = $this->getDataGenerator()->get_plugin_generator('core_question');

        $cat = $generator->create_question_category();

        $question1 = $generator->create_question('shortanswer', null, ['category' => $cat->id]);

        $loader = new random_question_loader(new qubaid_list([]));

        $filters = question_filter_test_helper::create_filters([$cat->id]);

        $this->assertTrue($loader->is_filtered_question_available($filters, $question1->id));

        $this->assertFalse($loader->is_filtered_question_available($filters, $question1->id));

        $this->assertFalse($loader->is_filtered_question_available($filters, -1));

    }

    /**

     * Data provider for the get_questions test.

     *

     * @return array testcases.

     */

    public static function get_questions_test_cases(): array {

        return [

                'empty category' => [

                        'categoryindex' => 'emptycat',

                        'includesubcategories' => false,

                        'usetagnames' => [],

                        'expectedquestionindexes' => []

                ],

                'single category' => [

                        'categoryindex' => 'cat1',

                        'includesubcategories' => false,

                        'usetagnames' => [],

                        'expectedquestionindexes' => ['cat1q1', 'cat1q2']

                ],

                'include sub category' => [

                        'categoryindex' => 'cat1',

                        'includesubcategories' => true,

                        'usetagnames' => [],

                        'expectedquestionindexes' => ['cat1q1', 'cat1q2', 'subcatq1', 'subcatq2']

                ],

                'single category with tags' => [

                        'categoryindex' => 'cat1',

                        'includesubcategories' => false,

                        'usetagnames' => ['cat1'],

                        'expectedquestionindexes' => ['cat1q1']

                ],

                'include sub category with tag on parent' => [

                        'categoryindex' => 'cat1',

                        'includesubcategories' => true,

                        'usetagnames' => ['cat1'],

                        'expectedquestionindexes' => ['cat1q1']

                ],

                'include sub category with tag on sub' => [

                        'categoryindex' => 'cat1',

                        'includesubcategories' => true,

                        'usetagnames' => ['subcat'],

                        'expectedquestionindexes' => ['subcatq1']

                ],

                'include sub category with same tag on parent and sub' => [

                        'categoryindex' => 'cat1',

                        'includesubcategories' => true,

                        'usetagnames' => ['foo'],

                        'expectedquestionindexes' => ['cat1q1', 'subcatq1']

                ],

                'include sub category with tag not matching' => [

                        'categoryindex' => 'cat1',

                        'includesubcategories' => true,

                        'usetagnames' => ['cat1', 'cat2'],

                        'expectedquestionindexes' => []

                ]

        ];

    }

    /**

     * Test the get_questions function with various parameter combinations.

     *

     * This function creates a data set as follows:

     *      Category: cat1

     *          Question: cat1q1

     *              Tags: 'cat1', 'foo'

     *          Question: cat1q2

     *      Category: cat2

     *          Question: cat2q1

     *              Tags: 'cat2', 'foo'

     *          Question: cat2q2

     *      Category: subcat

     *          Question: subcatq1

     *              Tags: 'subcat', 'foo'

     *          Question: subcatq2

     *          Parent: cat1

     *      Category: emptycat

     *

     * @dataProvider get_questions_test_cases

     * @param string $categoryindex The named index for the category to use

     * @param bool $includesubcategories If the search should include subcategories

     * @param string[] $usetagnames The tag names to include in the search

     * @param string[] $expectedquestionindexes The questions expected in the result

     */

    public function test_get_questions_variations(

            $categoryindex,

            $includesubcategories,

            $usetagnames,

            $expectedquestionindexes

    ): void {

        $this->resetAfterTest();

        $categories = [];

        $questions = [];

        $tagnames = [

                'cat1',

                'cat2',

                'subcat',

                'foo'

        ];

        $collid = \core_tag_collection::get_default();

        $tags = \core_tag_tag::create_if_missing($collid, $tagnames);

        $generator = $this->getDataGenerator()->get_plugin_generator('core_question');

        // First category and questions.

        [$category, $categoryquestions] = $this->create_category_and_questions(2, ['cat1', 'foo']);

        $categories['cat1'] = $category;

        $questions['cat1q1'] = $categoryquestions[0];

        $questions['cat1q2'] = $categoryquestions[1];

        // Second category and questions.

        [$category, $categoryquestions] = $this->create_category_and_questions(2, ['cat2', 'foo']);

        $categories['cat2'] = $category;

        $questions['cat2q1'] = $categoryquestions[0];

        $questions['cat2q2'] = $categoryquestions[1];

        // Sub category and questions.

        [$category, $categoryquestions] = $this->create_category_and_questions(2, ['subcat', 'foo'], $categories['cat1']);

        $categories['subcat'] = $category;

        $questions['subcatq1'] = $categoryquestions[0];

        $questions['subcatq2'] = $categoryquestions[1];

        // Empty category.

        [$category, $categoryquestions] = $this->create_category_and_questions(0);

        $categories['emptycat'] = $category;

        // Generate the arguments for the get_questions function.

        $category = $categories[$categoryindex];

        $tagids = array_map(function($tagname) use ($tags) {

            return $tags[$tagname]->id;

        }, $usetagnames);

        $loader = new random_question_loader(new qubaid_list([]));

        $filters = question_filter_test_helper::create_filters([$category->id], $includesubcategories, $tagids);

        $result = $loader->get_filtered_questions($filters);

        // Generate the expected question set.

        $expectedquestions = array_map(function($index) use ($questions) {

            return $questions[$index];

        }, $expectedquestionindexes);

        // Ensure the result matches what was expected.

        $this->assertCount(count($expectedquestions), $result);

        foreach ($expectedquestions as $question) {

            $this->assertEquals($result[$question->id]->id, $question->id);

            $this->assertEquals($result[$question->id]->category, $question->category);

        }

    }

    /**

     * get_questions should allow limiting and offsetting of the result set.

     */

    public function test_get_questions_with_limit_and_offset(): void {

        $this->resetAfterTest();

        $numberofquestions = 5;

        $includesubcategories = false;

        $tagids = [];

        $limit = 1;

        $offset = 0;

        $loader = new random_question_loader(new qubaid_list([]));

        [$category, $questions] = $this->create_category_and_questions($numberofquestions);

        // Add questionid as key to find them easily later.

        $questionsbyid = [];

        array_walk($questions, function (&$value) use (&$questionsbyid) {

            $questionsbyid[$value->id] = $value;

        });

        $filters = question_filter_test_helper::create_filters([$category->id], $includesubcategories, $tagids);

        for ($i = 0; $i < $numberofquestions; $i++) {

            $result = $loader->get_filtered_questions(

                    $filters,

                    $limit,

                    $offset

            );

            $this->assertCount($limit, $result);

            $actual = array_shift($result);

            $expected = $questionsbyid[$actual->id];

            $this->assertEquals($expected->id, $actual->id);

            $offset++;

        }

    }

    /**

     * get_questions should allow retrieving questions with only a subset of

     * fields populated.

     */

    public function test_get_questions_with_restricted_fields(): void {

        $this->resetAfterTest();

        $includesubcategories = false;

        $tagids = [];

        $limit = 10;

        $offset = 0;

        $fields = ['id', 'name'];

        $loader = new random_question_loader(new qubaid_list([]));

        [$category, $questions] = $this->create_category_and_questions(1);

        $filters = question_filter_test_helper::create_filters([$category->id], $includesubcategories, $tagids);

        $result = $loader->get_filtered_questions(

                $filters,

                $limit,

                $offset,

                $fields

        );

        $expectedquestion = array_shift($questions);

        $actualquestion = array_shift($result);

        $actualfields = get_object_vars($actualquestion);

        $actualfields = array_keys($actualfields);

        sort($actualfields);

        sort($fields);

        $this->assertEquals($fields, $actualfields);

    }

    /**

     * Data provider for the count_questions test.

     *

     * @return array testcases.

     */

    public static function count_questions_test_cases(): array {

        return [

                'empty category' => [

                        'categoryindex' => 'emptycat',

                        'includesubcategories' => false,

                        'usetagnames' => [],

                        'expectedcount' => 0

                ],

                'single category' => [

                        'categoryindex' => 'cat1',

                        'includesubcategories' => false,

                        'usetagnames' => [],

                        'expectedcount' => 2

                ],

                'include sub category' => [

                        'categoryindex' => 'cat1',

                        'includesubcategories' => true,

                        'usetagnames' => [],

                        'expectedcount' => 4

                ],

                'single category with tags' => [

                        'categoryindex' => 'cat1',

                        'includesubcategories' => false,

                        'usetagnames' => ['cat1'],

                        'expectedcount' => 1

                ],

                'include sub category with tag on parent' => [

                        'categoryindex' => 'cat1',

                        'includesubcategories' => true,

                        'usetagnames' => ['cat1'],

                        'expectedcount' => 1

                ],

                'include sub category with tag on sub' => [

                        'categoryindex' => 'cat1',

                        'includesubcategories' => true,

                        'usetagnames' => ['subcat'],

                        'expectedcount' => 1

                ],

                'include sub category with same tag on parent and sub' => [

                        'categoryindex' => 'cat1',

                        'includesubcategories' => true,

                        'usetagnames' => ['foo'],

                        'expectedcount' => 2

                ],

                'include sub category with tag not matching' => [

                        'categoryindex' => 'cat1',

                        'includesubcategories' => true,

                        'usetagnames' => ['cat1', 'cat2'],

                        'expectedcount' => 0

                ]

        ];

    }

    /**

     * Test the count_questions function with various parameter combinations.

     *

     * This function creates a data set as follows:

     *      Category: cat1

     *          Question: cat1q1

     *              Tags: 'cat1', 'foo'

     *          Question: cat1q2

     *      Category: cat2

     *          Question: cat2q1

     *              Tags: 'cat2', 'foo'

     *          Question: cat2q2

     *      Category: subcat

     *          Question: subcatq1

     *              Tags: 'subcat', 'foo'

     *          Question: subcatq2

     *          Parent: cat1

     *      Category: emptycat

     *

     * @dataProvider count_questions_test_cases

     * @param string $categoryindex The named index for the category to use

     * @param bool $includesubcategories If the search should include subcategories

     * @param string[] $usetagnames The tag names to include in the search

     * @param int $expectedcount The number of questions expected in the result

     */

    public function test_count_questions_variations(

            $categoryindex,

            $includesubcategories,

            $usetagnames,

            $expectedcount

    ): void {

        $this->resetAfterTest();

        $categories = [];

        $questions = [];

        $tagnames = [

                'cat1',

                'cat2',

                'subcat',

                'foo'

        ];

        $collid = \core_tag_collection::get_default();

        $tags = \core_tag_tag::create_if_missing($collid, $tagnames);

        $generator = $this->getDataGenerator()->get_plugin_generator('core_question');

        // First category and questions.

        [$category, $categoryquestions] = $this->create_category_and_questions(2, ['cat1', 'foo']);

        $categories['cat1'] = $category;

        $questions['cat1q1'] = $categoryquestions[0];

        $questions['cat1q2'] = $categoryquestions[1];

        // Second category and questions.

        [$category, $categoryquestions] = $this->create_category_and_questions(2, ['cat2', 'foo']);

        $categories['cat2'] = $category;

        $questions['cat2q1'] = $categoryquestions[0];

        $questions['cat2q2'] = $categoryquestions[1];

        // Sub category and questions.

        [$category, $categoryquestions] = $this->create_category_and_questions(2, ['subcat', 'foo'], $categories['cat1']);

        $categories['subcat'] = $category;

        $questions['subcatq1'] = $categoryquestions[0];

        $questions['subcatq2'] = $categoryquestions[1];

        // Empty category.

        [$category, $categoryquestions] = $this->create_category_and_questions(0);

        $categories['emptycat'] = $category;

        // Generate the arguments for the get_questions function.

        $category = $categories[$categoryindex];

        $tagids = array_map(function($tagname) use ($tags) {

            return $tags[$tagname]->id;

        }, $usetagnames);

        $filters = question_filter_test_helper::create_filters([$category->id], $includesubcategories, $tagids);

        $loader = new random_question_loader(new qubaid_list([]));

        $result = $loader->count_filtered_questions($filters);

        // Ensure the result matches what was expected.

        $this->assertEquals($expectedcount, $result);

    }

    /**

     * Create a question category and create questions in that category. Tag

     * the first question in each category with the given tags.

     *

     * @param int $questioncount How many questions to create.

     * @param string[] $tagnames The list of tags to use.

     * @param stdClass|null $parentcategory The category to set as the parent of the created category.

     * @return array The category and questions.

     */

    protected function create_category_and_questions($questioncount, $tagnames = [], $parentcategory = null): array {

        $generator = $this->getDataGenerator()->get_plugin_generator('core_question');

        if ($parentcategory) {

            $catparams = ['parent' => $parentcategory->id];

        } else {

            $catparams = [];

        }

        $category = $generator->create_question_category($catparams);

        $questions = [];

        for ($i = 0; $i < $questioncount; $i++) {

            $questions[] = $generator->create_question('shortanswer', null, ['category' => $category->id]);

        }

        if (!empty($tagnames) && !empty($questions)) {

            $context = \context::instance_by_id($category->contextid);

            \core_tag_tag::set_item_tags('core_question', 'question', $questions[0]->id, $context, $tagnames);

        }

        return [$category, $questions];

    }

    /**

     * Test that the random question loader excludes questions with invalid types.

     * @return void

     * @throws \dml_exception

     */

    public function test_invalid_questions_are_excluded(): void {

        global $DB;

        $this->resetAfterTest();

        [$category, $questions] = $this->create_category_and_questions(4);

        $loader = new random_question_loader(new qubaid_list([]));

        $filters = question_filter_test_helper::create_filters([$category->id], false, []);

        // Update one of the questions to have an invalid type.

        $invalid = $questions[0];

        $invalid->qtype = 'invalid';

        $DB->update_record('question', $invalid);

        // Assert that we get 1 less result back because the invalid type is excluded.

        $result = $loader->get_filtered_questions($filters);

        $this->assertEquals(count($questions) - 1, count($result));

    }

}