TestHttpClientMiddleware.php

<?php

namespace Drupal\Core\Test\HttpClientMiddleware;

use Drupal\Core\Utility\Error;
use Psr\Http\Message\RequestInterface;
use Psr\Http\Message\ResponseInterface;

/**
 * Overrides the User-Agent HTTP header for outbound HTTP requests.
 */
class TestHttpClientMiddleware {
    
    /**
     * HTTP middleware that replaces the user agent for test requests.
     */
    public function __invoke() {
        // If the database prefix is being used to run the tests in a copied
        // database, then set the User-Agent header to the database prefix so that
        // any calls to other Drupal pages will run the test-prefixed database. The
        // user agent is used to ensure that multiple testing sessions running at
        // the same time won't interfere with each other as they would if the
        // database prefix were stored statically in a file or database variable.
        return function ($handler) {
            return function (RequestInterface $request, array $options) use ($handler) {
                if ($user_agent = drupal_generate_test_ua(drupal_valid_test_ua())) {
                    $request = $request->withHeader('User-Agent', $user_agent);
                }
                return $handler($request, $options)->then(function (ResponseInterface $response) {
                    if (!drupal_valid_test_ua()) {
                        return $response;
                    }
                    if (!empty($response->getHeader('X-Drupal-Wait-Terminate')[0])) {
                        $lock = \Drupal::lock();
                        if (!$lock->acquire('test_wait_terminate')) {
                            $lock->wait('test_wait_terminate');
                        }
                        $lock->release('test_wait_terminate');
                    }
                    $headers = $response->getHeaders();
                    foreach ($headers as $header_name => $header_values) {
                        if (preg_match('/^X-Drupal-Assertion-[0-9]+$/', $header_name, $matches)) {
                            foreach ($header_values as $header_value) {
                                $parameters = unserialize(urldecode($header_value));
                                if (count($parameters) === 3) {
                                    if ($parameters[1] === 'User deprecated function') {
                                        // Fire the same deprecation message to allow it to be
                                        // collected by
                                        // \Drupal\TestTools\Extension\DeprecationBridge\DeprecationHandler::collectActualDeprecation().
                                        // phpcs:ignore Drupal.Semantics.FunctionTriggerError
                                        @trigger_error((string) $parameters[0], E_USER_DEPRECATED);
                                    }
                                    else {
                                        throw new \Exception($parameters[1] . ': ' . $parameters[0] . "\n" . Error::formatBacktrace([
                                            $parameters[2],
                                        ]));
                                    }
                                }
                                else {
                                    throw new \Exception('Error thrown with the wrong amount of parameters.');
                                }
                            }
                        }
                    }
                    return $response;
                });
            };
        };
    }

}