class PathProcessorTest

class PathProcessorTest implements InboundPathProcessorInterface, OutboundPathProcessorInterface {
    
    /**
     * {@inheritdoc}
     */
    public function processInbound($path, Request $request) {
        // Rewrite user/username to user/uid.
        if (preg_match('!^/user/([^/]+)(/.*)?!', $path, $matches)) {
            if ($account = user_load_by_name($matches[1])) {
                $matches += [
                    2 => '',
                ];
                $path = '/user/' . $account->id() . $matches[2];
            }
        }
        if ($path == '/url-alter-test/bar') {
            $path = '/url-alter-test/foo';
        }
        return $path;
    }
    
    /**
     * {@inheritdoc}
     */
    public function processOutbound($path, &$options = [], Request $request = NULL, BubbleableMetadata $bubbleable_metadata = NULL) {
        // Rewrite user/uid to user/username.
        if (preg_match('!^/user/([0-9]+)(/.*)?!', $path, $matches)) {
            if ($account = User::load($matches[1])) {
                $matches += [
                    2 => '',
                ];
                $path = '/user/' . $account->getAccountName() . $matches[2];
                if ($bubbleable_metadata) {
                    $bubbleable_metadata->addCacheTags($account->getCacheTags());
                }
            }
        }
        // Verify that $options are alterable.
        if ($path == '/user/login') {
            $options['query']['foo'] = 'bar';
        }
        return $path;
    }

}