ThemeUpdateTest.php

<?php

namespace Drupal\Tests\system\Functional\Theme;

use Drupal\Tests\BrowserTestBase;
use Drupal\Tests\UpdatePathTestTrait;

/**
 * Tests low-level theme functions.
 *
 * @group Theme
 */
class ThemeUpdateTest extends BrowserTestBase {
    use UpdatePathTestTrait;
    
    /**
     * {@inheritdoc}
     */
    protected $defaultTheme = 'starterkit_theme';
    
    /**
     * Ensures preprocess functions run even for suggestion implementations.
     *
     * The theme hook used by this test has its base preprocess function in a
     * separate file, so this test also ensures that the file is correctly loaded
     * when needed.
     */
    public function testThemeUpdates() {
        \Drupal::service('module_installer')->install([
            'test_module_required_by_theme',
        ]);
        $this->rebuildAll();
        \Drupal::state()->set('test_theme_depending_on_modules.system_info_alter', [
            'dependencies' => [
                'test_module_required_by_theme',
                'stark',
            ],
        ]);
        \Drupal::service('theme_installer')->install([
            'test_theme_depending_on_modules',
        ]);
        $this->assertTrue(\Drupal::service('theme_handler')->themeExists('test_theme_depending_on_modules'), 'test_theme_depending_on_modules theme installed');
        \Drupal::state()->set('test_theme_depending_on_modules.system_info_alter', FALSE);
        \Drupal::state()->set('test_theme_depending_on_modules.post_update', TRUE);
        $this->assertFalse(\Drupal::moduleHandler()->moduleExists('test_another_module_required_by_theme'));
        $this->runUpdates();
        $this->assertTrue(\Drupal::moduleHandler()->moduleExists('test_another_module_required_by_theme'));
        $this->assertSession()
            ->addressEquals('update.php/results');
        $this->assertSession()
            ->responseContains('test_theme_depending_on_modules theme');
        $this->assertSession()
            ->responseContains('Post update message from theme post update function');
    }
    
    /**
     * {@inheritdoc}
     */
    protected function doSelectionTest() {
        // Ensure that the theme's post update appears as expected.
        $this->assertSession()
            ->responseContains('test_theme_depending_on_modules theme');
        $this->assertSession()
            ->responseContains('Install a dependent module.');
    }

}