ThemeTokenTest.php

<?php

namespace Drupal\Tests\system\Functional\Theme;

use Drupal\Tests\BrowserTestBase;

/**
 * Tests the generation of 'theme_token' key in Drupal settings.
 *
 * @group Theme
 */
class ThemeTokenTest extends BrowserTestBase {
    
    /**
     * We want to visit the 'admin/structure/block' page.
     *
     * @var array
     */
    protected static $modules = [
        'block',
    ];
    
    /**
     * {@inheritdoc}
     */
    protected $defaultTheme = 'stark';
    
    /**
     * {@inheritdoc}
     */
    protected function setUp() : void {
        parent::setUp();
        $account = $this->drupalCreateUser([
            'administer blocks',
            'view the administration theme',
        ]);
        $this->drupalLogin($account);
    }
    
    /**
     * Tests if the 'theme_token' key of 'ajaxPageState' is computed.
     */
    public function testThemeToken() {
        // Visit the block administrative page with default theme. We use that page
        // because 'misc/ajax.js' is loaded there and we can test the token
        // generation.
        $this->drupalGet('admin/structure/block');
        $settings = $this->getDrupalSettings();
        $this->assertNull($settings['ajaxPageState']['theme_token']);
        // Install 'claro' and configure it as administrative theme.
        $this->container
            ->get('theme_installer')
            ->install([
            'claro',
        ]);
        $this->config('system.theme')
            ->set('admin', 'claro')
            ->save();
        // Revisit the page. This time the page is displayed using the 'claro' theme
        // and that is different from the default theme ('stark').
        $this->drupalGet('admin/structure/block');
        $settings = $this->getDrupalSettings();
        $this->assertNotNull($settings['ajaxPageState']['theme_token']);
        // The CSRF token is a 43 length string.
        $this->assertIsString($settings['ajaxPageState']['theme_token']);
        $this->assertEquals(43, strlen($settings['ajaxPageState']['theme_token']));
    }

}