BlockRenderOrderTest.php

<?php

namespace Drupal\Tests\block\Functional;

use Drupal\Component\Utility\Html;
use Drupal\Tests\BrowserTestBase;

/**
 * Tests blocks are being rendered in order by weight.
 *
 * @group block
 */
class BlockRenderOrderTest extends BrowserTestBase {
    
    /**
     * Modules to install.
     *
     * @var array
     */
    protected static $modules = [
        'node',
        'block',
    ];
    
    /**
     * {@inheritdoc}
     */
    protected $defaultTheme = 'stark';
    
    /**
     * {@inheritdoc}
     */
    protected function setUp() : void {
        parent::setUp();
        // Create a test user.
        $end_user = $this->drupalCreateUser([
            'access content',
        ]);
        $this->drupalLogin($end_user);
    }
    
    /**
     * Tests the render order of the blocks.
     */
    public function testBlockRenderOrder() {
        // Enable test blocks and place them in the same region.
        $region = 'header';
        $test_blocks = [
            'stark_powered' => [
                'weight' => '-3',
                'id' => 'stark_powered',
                'label' => 'Test block A',
            ],
            'stark_by' => [
                'weight' => '3',
                'id' => 'stark_by',
                'label' => 'Test block C',
            ],
            'stark_drupal' => [
                'weight' => '3',
                'id' => 'stark_drupal',
                'label' => 'Test block B',
            ],
        ];
        // Place the test blocks.
        foreach ($test_blocks as $test_block) {
            $this->drupalPlaceBlock('system_powered_by_block', [
                'label' => $test_block['label'],
                'region' => $region,
                'weight' => $test_block['weight'],
                'id' => $test_block['id'],
            ]);
        }
        $this->drupalGet('');
        $test_content = $this->getSession()
            ->getPage()
            ->getContent();
        $controller = $this->container
            ->get('entity_type.manager')
            ->getStorage('block');
        foreach ($controller->loadMultiple() as $return_block) {
            $id = $return_block->id();
            if ($return_block_weight = $return_block->getWeight()) {
                $this->assertSame((int) $test_blocks[$id]['weight'], $return_block_weight, 'Block weight is set as "' . $return_block_weight . '" for ' . $id . ' block.');
                $position[$id] = strpos($test_content, Html::getClass('block-' . $test_blocks[$id]['id']));
            }
        }
        // Verify that blocks with different weight are rendered in the correct
        // order.
        $this->assertLessThan($position['stark_by'], $position['stark_powered']);
        // Verify that blocks with identical weight are rendered in alphabetical
        // order.
        $this->assertLessThan($position['stark_by'], $position['stark_drupal']);
    }

}