EngineNyanCatTest.php

<?php

namespace Drupal\Tests\system\Functional\Theme;

use Drupal\Tests\BrowserTestBase;

/**
 * Tests the multi theme engine support.
 *
 * @group Theme
 */
class EngineNyanCatTest extends BrowserTestBase {
    
    /**
     * Modules to enable.
     *
     * @var array
     */
    protected static $modules = [
        'theme_test',
    ];
    
    /**
     * {@inheritdoc}
     */
    protected $defaultTheme = 'stark';
    
    /**
     * {@inheritdoc}
     */
    protected function setUp() : void {
        parent::setUp();
        \Drupal::service('theme_installer')->install([
            'test_theme_nyan_cat_engine',
        ]);
    }
    
    /**
     * Ensures a theme's template is overridable based on the 'template' filename.
     *
     * @group legacy
     *
     * @todo https://www.drupal.org/project/drupal/issues/3246981 Remove
     *   nyan_cat_init() and the legacy group and expected deprecation from this
     *   test.
     */
    public function testTemplateOverride() {
        $this->expectDeprecation('THEME_ENGINE_init() is deprecated in drupal:9.3.0 and removed in drupal:10.0.0. There is no replacement. See https://www.drupal.org/node/3246978');
        $this->config('system.theme')
            ->set('default', 'test_theme_nyan_cat_engine')
            ->save();
        $this->drupalGet('theme-test/template-test');
        $this->assertSession()
            ->pageTextContains('Success: Template overridden with Nyan Cat theme. All of them');
    }

}