ReplicaKillSwitchTest.php

<?php

namespace Drupal\KernelTests\Core\Database;

use Drupal\Core\Database\Database;
use Drupal\Core\DrupalKernel;
use Drupal\Core\Site\Settings;
use Drupal\KernelTests\KernelTestBase;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpKernel\HttpKernelInterface;
use Symfony\Component\HttpKernel\Event\RequestEvent;

/**
 * Tests that ReplicaKillSwitch functions correctly.
 *
 * @group system
 */
class ReplicaKillSwitchTest extends KernelTestBase {
    
    /**
     * Tests database.replica_kill_switch service.
     */
    public function testSystemInitIgnoresSecondaries() {
        // Clone the master credentials to a replica connection.
        // Note this will result in two independent connection objects that happen
        // to point to the same place.
        $connection_info = Database::getConnectionInfo('default');
        Database::addConnectionInfo('default', 'replica', $connection_info['default']);
        
        /** @var \Drupal\Core\Database\ReplicaKillSwitch $service */
        $service = \Drupal::service('database.replica_kill_switch');
        $service->trigger();
        $class_loader = (require $this->root . '/autoload.php');
        $kernel = new DrupalKernel('testing', $class_loader, FALSE);
        $event = new RequestEvent($kernel, Request::create('http://example.com'), HttpKernelInterface::MAIN_REQUEST);
        $service->checkReplicaServer($event);
        $db1 = Database::getConnection('default', 'default');
        $db2 = Database::getConnection('replica', 'default');
        $this->assertSame($db1, $db2, 'System Init ignores secondaries when requested.');
        // Makes sure that session value set right.
        $session = \Drupal::service('session');
        $this->assertTrue($session->has('ignore_replica_server'));
        $expected = \Drupal::time()->getRequestTime() + Settings::get('maximum_replication_lag', 300);
        $this->assertEquals($expected, $session->get('ignore_replica_server'));
    }

}