Try Rector Online | Rector - Automated Way to Instantly Upgrade and Refactor any PHP code

Rector run Failed:

{ "totals": { "changed_files": 0, "errors": 1 }, "errors": [ { "message": "System error: \"Call to undefined method Rector\\PhpParser\\Printer\\BetterStandardPrinter::pInterpolatedStringPart()\"\nRun Rector with \"--debug\" option and post the report here: https://github.com/rectorphp/rector/issues/new", "file": "/var/www/storage/demo/js26bq7wx3wglyaeny3s/rector_analyzed_file.php", "line": 579 } ] }

Run Rector on your code to see what it can do for you:

PHP snippet to change

<?php

$markdown = 'a long string';

// parse tags
$markdown = preg_replace_callback(
    '/\[([a-zA-Z0-9._-]+)\]/im',
    function (array $matches): string {
        $match = $matches[1];
        $className = strtolower(Toolkit::toSlug($match));

        return "<span class='tag tag-{$className}'>{$match}</span>";
    },
    (string) $markdown
);

Config rector.php

<?php

use Rector\Config\RectorConfig;
use Rector\TypeDeclaration\Rector\Property\TypedPropertyFromAssignsRector;
use Rector\ValueObject\PhpVersion;

return RectorConfig::configure()
    ->withRules([
        \Rector\DeadCode\Rector\Assign\RemoveDoubleAssignRector::class
    ])
    // demonstrate specific PHP version
    ->withPhpVersion(PhpVersion::PHP_81);

Rector version: 2.2.14 - released at 2025-12-09 11:53