paratest with multiple db instances

.bashrc

alias paratest='php bin/console test:init:database:pool -e=test 10 && vendor/bin/paratest -f -p 10 —max-batch-size 5 —coverage-html=build/coverage'

AbstractFunctionalTestCase.php

abstract class AbstractFunctionalTestCase extends AbstractTestCase
{
    /**
     * @var ContainerInterface
     */
    protected $container;

    /**
     * @var Client
     */
    protected $client;

    /**
     * @var EntityManager
     */
    protected $em;

    public function setUp()
    {
        parent::setUp();

        $this->client = static::createClient();
        $this->container = $this->client->getContainer();
        $this->em = $this->container->get('doctrine.orm.entity_manager');

        $this->container->get('database_pool')->loadDatabaseFromDump();
    }
}

config.yml

parameters:
  dbname:   "@=service('database_pool').get()"

config_test.yml

services:
    database_pool:
        class: AppBundle\Test\DatabasePool
        arguments:
            - "@service_container"
            - "%database_name%"
            - "%database_host%"
            - "%database_port%"
            - "%database_user%"
            - "%database_password%"
    doctrine.dbal.default_connection:
        class: Doctrine\DBAL\Portability\Connection
        factory: [Doctrine\DBAL\DriverManager, getConnection]
        arguments:
            - driver:   pdo_mysql
              host:     "%database_host%"
              port:     "%database_port%"
              dbname:   "@=service('database_pool').get()"
              user:     "%database_user%"
              password: "%database_password%"

DatabasePool.php

<?php

namespace AppBundle\Test;

use AppKernel;
use Doctrine\Common\DataFixtures\Executor\ORMExecutor;
use Doctrine\Common\DataFixtures\Loader;
use Doctrine\Common\DataFixtures\Purger\ORMPurger;
use Symfony\Bundle\FrameworkBundle\Console\Application;
use Symfony\Component\Console\Input\ArrayInput;
use Symfony\Component\Console\Output\BufferedOutput;
use Symfony\Component\DependencyInjection\ContainerInterface;

class DatabasePool
{
    const DB_DUMP_FILE = 'db-dump.sql';

    /**
     * @var ContainerInterface
     */
    protected $container;

    /**
     * @var string
     */
    protected $databaseName;

    /**
     * @var string
     */
    protected $databaseHost;

    /**
     * @var int
     */
    protected $databasePort;

    /**
     * @var string
     */
    protected $databaseUser;

    /**
     * @var string
     */
    protected $databasePassword;

    /**
     * @var string
     */
    protected $createSchemaQueries;

    protected static $pdo;

    public function __construct(ContainerInterface $container, $databaseName, $databaseHost, $databasePort, $databaseUser, $databasePassword)
    {
        $this->container = $container;
        $this->databaseName = $databaseName;
        $this->databaseHost = $databaseHost;
        $this->databasePort = $databasePort;
        $this->databaseUser = $databaseUser;
        $this->databasePassword = $databasePassword;

        if (is_null(self::$pdo)) {
            self::$pdo = new \PDO("mysql:host=$this->databaseHost;port=$this->databasePort", $this->databaseUser, $this->databasePassword);
            self::$pdo->setAttribute(\PDO::ATTR_EMULATE_PREPARES, 1);
        }
    }

    public function get()
    {
        $pooledDatabases = $this->getPool();

        $dbName = $this->databaseName;

        if (getenv('TEST_TOKEN') !== false) {
            $token = getenv('TEST_TOKEN');

            if ($token > 0) {
                $dbName = $this->getDatabasePrefix() . getenv('TEST_TOKEN');
            }
        }

        if (count($pooledDatabases) == 0) {
//            throw new \RuntimeException("Database pool is empty");
        } else {
            if (in_array($dbName, $pooledDatabases)) {
                return $dbName;
            }

            throw new \RuntimeException("Test database '$dbName' not found");
        }
    }

    public function fillPool($size)
    {
        if ($size <= 0) {
            throw new \UnexpectedValueException('Pool size must be greater than 0');
        }

        foreach ($this->getPool() as $pooledDatabase) {
            self::$pdo->exec("DROP DATABASE {$pooledDatabase}");
        }

        $databaseName = $this->getDatabasePrefix();
        $this->createDatabase($databaseName);
        $this->createSchema();
        $this->loadFixtures();
        $this->dumpDatabase();

        for ($i = 1; $i <= $size; $i++) {
            $databaseName = $this->getDatabasePrefix() . $i;
            $this->createDatabase($databaseName);
        }
    }

    private function dumpDatabase()
    {
        $command = "mysqldump --opt --lock-tables=false --port=$this->databasePort --host=$this->databaseHost --user=$this->databaseUser --password=$this->databasePassword";

        $command .= sprintf(' %s > %s', $this->databaseName, $this->getDbDumpFilename($this->container));
        $command .= ' 2>/dev/null';

        exec($command);
    }

    public function loadDatabaseFromDump()
    {
        $command = "mysql --port=$this->databasePort --host=$this->databaseHost --user=$this->databaseUser --password=$this->databasePassword";

        $command .= sprintf(' %s < %s', $this->get(), $this->getDbDumpFilename($this->container));
        $command .= ' 2>/dev/null';

        exec($command);
    }

    /**
     * @return array
     */
    protected function getPool()
    {
        $sql = "
        SELECT `schema_name` 
        FROM information_schema.schemata 
        WHERE `schema_name` LIKE '{$this->getDatabasePrefix()}%' 
        ORDER BY `schema_name` DESC
        ";

        return self::$pdo->query($sql)->fetchAll(\PDO::FETCH_COLUMN);
    }

    protected function createDatabase($name)
    {
        self::$pdo->query("CREATE DATABASE IF NOT EXISTS $name");
        self::$pdo->query("USE $name");
    }

    protected function executeCommand($commandName, $parameters = [])
    {
        $kernel = new AppKernel('test', true);

        $application = new Application($kernel);
        $application->setAutoExit(false);

        $input = new ArrayInput(array_merge(['command' => $commandName], $parameters));

        $output = new BufferedOutput();
        $application->run($input, $output);

        return $output->fetch();
    }

    protected function getDatabasePrefix()
    {
        return $this->databaseName;
    }

    protected function createSchema()
    {
        $query = $this->executeCommand('doctrine:schema:create', ['--dump-sql' => true]);
        self::$pdo->query($query);
    }

    protected function loadFixtures()
    {
        $fixturesLoader = new Loader();

        $fixturesLoader->loadFromDirectory($this->container->getParameter('kernel.root_dir') . '/../tests/Fixtures');

        foreach ($fixturesLoader->getFixtures() as $fixture) {
            if (method_exists($fixture, 'setContainer')) {
                $fixture->setContainer($this->container);
            }
        }

        $em = $this->container->get('doctrine.orm.entity_manager');

        $purger = new ORMPurger($em);
        $purger->setPurgeMode(ORMPurger::PURGE_MODE_DELETE);

        $executor = new ORMExecutor($em, $purger);
        $executor->execute($fixturesLoader->getFixtures());
    }

    public function closeConnection()
    {
        self::$pdo = null;
    }

    public static function getDbDumpFilename(ContainerInterface $container)
    {
        return $container->getParameter('kernel.cache_dir') . '/' . self::DB_DUMP_FILE;
    }
}

InitDatabasePoolCommand.php

<?php

namespace AppBundle\Command\Test;

use AppBundle\Test\DatabasePool;
use Symfony\Bundle\FrameworkBundle\Command\ContainerAwareCommand;
use Symfony\Component\Console\Input\InputArgument;
use Symfony\Component\Console\Input\InputInterface;
use Symfony\Component\Console\Output\OutputInterface;

class InitDatabasePoolCommand extends ContainerAwareCommand
{
    protected function configure()
    {
        $this
            ->setName('test:init:database:pool')
            ->addArgument('size', InputArgument::OPTIONAL, 'amount db in pool', 10)
            ->setDescription('Create poll with testing databases');
    }

    protected function execute(InputInterface $input, OutputInterface $output)
    {
        $container = $this->getContainer();

        $pool = new DatabasePool(
            $container,
            $container->getParameter('database_name'),
            $container->getParameter('database_host'),
            $container->getParameter('database_port'),
            $container->getParameter('database_user'),
            $container->getParameter('database_password')
        );

        $pool->fillPool($input->getArgument('size'));
    }
}

https://locastic.com/blog/speed-up-database-refreshing-in-phpunit-tests