A Symfony compiler pass to set the default transaction isolation level on Doctrine\DBAL\Connection

DoctrineCompilerPass.php

<?php

declare(strict_types=1);

namespace App;

use Doctrine\DBAL\Connection;
use Doctrine\DBAL\TransactionIsolationLevel;
use Symfony\Component\DependencyInjection\Compiler\CompilerPassInterface;
use Symfony\Component\DependencyInjection\ContainerBuilder;

class DoctrineCompilerPass implements CompilerPassInterface
{
    public function process(ContainerBuilder $container)
    {
        $container
            ->getDefinition('doctrine.dbal.default_connection')
            ->setConfigurator([self::class, 'setDefaultTransactionIsolationLevel']);
    }

    public static function setDefaultTransactionIsolationLevel(Connection $connection) : void
    {
        $connection->setTransactionIsolation(TransactionIsolationLevel::READ_COMMITTED);
    }
}