MainContentFallbackTest.php

<?php

namespace Drupal\Tests\system\Functional\System;

use Drupal\Tests\BrowserTestBase;

/**
 * Test SimplePageVariant main content rendering fallback page display variant.
 *
 * @group system
 */
class MainContentFallbackTest extends BrowserTestBase {
    
    /**
     * Modules to enable.
     *
     * @var array
     */
    protected static $modules = [
        'block',
        'system_test',
    ];
    
    /**
     * {@inheritdoc}
     */
    protected $defaultTheme = 'stark';
    protected $adminUser;
    protected $webUser;
    
    /**
     * {@inheritdoc}
     */
    protected function setUp() : void {
        parent::setUp();
        // Create and log in admin user.
        $this->adminUser = $this->drupalCreateUser([
            'access administration pages',
            'administer site configuration',
            'administer modules',
        ]);
        $this->drupalLogin($this->adminUser);
        // Create a web user.
        $this->webUser = $this->drupalCreateUser([
            'access user profiles',
        ]);
    }
    
    /**
     * Tests availability of main content: Drupal falls back to SimplePageVariant.
     */
    public function testMainContentFallback() {
        $edit = [];
        // Uninstall the block module.
        $edit['uninstall[block]'] = 'block';
        $this->drupalGet('admin/modules/uninstall');
        $this->submitForm($edit, 'Uninstall');
        $this->submitForm([], 'Uninstall');
        $this->assertSession()
            ->pageTextContains('The selected modules have been uninstalled.');
        $this->rebuildContainer();
        $this->assertFalse(\Drupal::moduleHandler()->moduleExists('block'), 'Block module uninstall.');
        // When Block module is not installed and BlockPageVariant is not available,
        // Drupal should fall back to SimplePageVariant. Both for the admin and the
        // front-end theme.
        $this->drupalGet('admin/config/system/site-information');
        $this->assertSession()
            ->fieldExists('site_name');
        $this->drupalGet('system-test/main-content-fallback');
        $this->assertSession()
            ->pageTextContains('Content to test main content fallback');
        // Request a user* page and see if it is displayed.
        $this->drupalLogin($this->webUser);
        $this->drupalGet('user/' . $this->webUser
            ->id() . '/edit');
        $this->assertSession()
            ->fieldExists('mail');
        // Enable the block module again.
        $this->drupalLogin($this->adminUser);
        $edit = [];
        $edit['modules[block][enable]'] = 'block';
        $this->drupalGet('admin/modules');
        $this->submitForm($edit, 'Install');
        $this->assertSession()
            ->pageTextContains('Module Block has been enabled.');
        $this->rebuildContainer();
        $this->assertTrue(\Drupal::moduleHandler()->moduleExists('block'), 'Block module re-enabled.');
    }

}