Add pseudo test class to allow to populate DB (#6478)

Normal use will not do anything other than succeed!
```
php $HUMHUB_VENDOR_BIN/codecept run unit LoadDbTest
```

However, if run with the environment variable HUMHUB_DB_INITIALIZE set, then the default fixtures will be loaded and not unloaded after the test.
```
HUMHUB_DB_INITIALIZE= php $HUMHUB_VENDOR_BIN/codecept run unit LoadDbTest
```

CHANGELOG-DEV.md

@@ -3,6 +3,7 @@ HumHub Changelog
 
 1.15.0-beta.2 (Unreleased)
 --------------------------
+- Enh #6478: Add pseudo test class to allow population of DB with standard test data
 - Enh #6480: Convert assert* and db* methods to static, in line with general usage pattern
 - Enh #6505: Introduce Application interface; now also fire the `onInit` event when the web application has initialized
 - Fix #6502: Link notification for pending space approval to manage page

protected/humhub/tests/codeception/unit/LoadDbTest.php

@@ -0,0 +1,86 @@
+<?php
+
+/*
+ * @link      https://www.humhub.org/
+ * @copyright Copyright (c) 2023 HumHub GmbH & Co. KG
+ * @license   https://www.humhub.com/licences
+ */
+
+namespace humhub\tests\codeception\unit;
+
+use Codeception\Exception\InjectionException;
+use Codeception\Exception\ModuleException;
+use Codeception\Lib\Console\Output;
+use Codeception\Lib\ModuleContainer;
+use Codeception\Module\Yii2;
+use Codeception\Test\Metadata;
+use tests\codeception\_support\HumHubDbTestCase;
+use Yii;
+use humhub\modules\queue\models\QueueExclusive;
+
+/**
+ * Test Debugging DbLoad Helper
+ *
+ * Use this test to fill up the database with fixture test data to manually debug
+ *
+ * Example usage:
+ * ```
+ * HUMHUB_DB_INITIALIZE= php $HUMHUB_VENDOR_BIN/codecept run unit LoadDbTest
+ * ```
+ *
+ * @since 1.15
+ */
+class LoadDbTest extends HumHubDbTestCase
+{
+    protected bool $humhubLoadDb = false;
+    protected static Output $humhubConsole;
+
+    public function _fixtures(...$args): array
+    {
+        if (false !== getenv('HUMHUB_DB_INITIALIZE') || in_array('--load', $_SERVER['argv'], true)) {
+            $this->humhubLoadDb = true;
+            $this->fixtureConfig = ['default'];
+
+            foreach (['queue', QueueExclusive::tableName()] as $table) {
+                self::dbDelete($table);
+            }
+
+            self::$humhubConsole->writeln(sprintf(' - Going to load fixtures: %s ...', implode(', ', $this->fixtureConfig)));
+        }
+
+        return parent::_fixtures();
+    }
+
+
+    public static function setUpBeforeClass(...$args): void
+    {
+        self::$humhubConsole = new Output([]);
+
+        parent::setUpBeforeClass();
+    }
+
+    /**
+     * @throws InjectionException
+     * @throws ModuleException
+     */
+    public function testLoadFixtures()
+    {
+        /**
+         * @var Yii2 $yii2
+         * @var Metadata $metadata
+         * @var ModuleContainer $service
+         */
+        $metadata = $this->getMetadata();
+        $service = $metadata->getService('modules');
+        $yii2 = $service->getModule('Yii2');
+
+        if ($this->humhubLoadDb) {
+            static::assertNotEmpty($yii2->loadedFixtures);
+
+            // prevent fixtures from being unloaded
+            $yii2->loadedFixtures = [];
+        } else {
+            static::assertEmpty($yii2->loadedFixtures);
+        }
+    }
+}