Add Composer autoloading functions and PHPStan for testing

vendor/symfony/contracts/Service/ServiceSubscriberInterface.php

@@ -0,0 +1,53 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Contracts\Service;
+
+/**
+ * A ServiceSubscriber exposes its dependencies via the static {@link getSubscribedServices} method.
+ *
+ * The getSubscribedServices method returns an array of service types required by such instances,
+ * optionally keyed by the service names used internally. Service types that start with an interrogation
+ * mark "?" are optional, while the other ones are mandatory service dependencies.
+ *
+ * The injected service locators SHOULD NOT allow access to any other services not specified by the method.
+ *
+ * It is expected that ServiceSubscriber instances consume PSR-11-based service locators internally.
+ * This interface does not dictate any injection method for these service locators, although constructor
+ * injection is recommended.
+ *
+ * @author Nicolas Grekas <p@tchwork.com>
+ */
+interface ServiceSubscriberInterface
+{
+    /**
+     * Returns an array of service types required by such instances, optionally keyed by the service names used internally.
+     *
+     * For mandatory dependencies:
+     *
+     *  * array('logger' => 'Psr\Log\LoggerInterface') means the objects use the "logger" name
+     *    internally to fetch a service which must implement Psr\Log\LoggerInterface.
+     *  * array('loggers' => 'Psr\Log\LoggerInterface[]') means the objects use the "loggers" name
+     *    internally to fetch an iterable of Psr\Log\LoggerInterface instances.
+     *  * array('Psr\Log\LoggerInterface') is a shortcut for
+     *  * array('Psr\Log\LoggerInterface' => 'Psr\Log\LoggerInterface')
+     *
+     * otherwise:
+     *
+     *  * array('logger' => '?Psr\Log\LoggerInterface') denotes an optional dependency
+     *  * array('loggers' => '?Psr\Log\LoggerInterface[]') denotes an optional iterable dependency
+     *  * array('?Psr\Log\LoggerInterface') is a shortcut for
+     *  * array('Psr\Log\LoggerInterface' => '?Psr\Log\LoggerInterface')
+     *
+     * @return array The required service types, optionally keyed by service names
+     */
+    public static function getSubscribedServices();
+}