Replace null key in array_key_exists with empty string
-array_key_exists(null, $array);
+array_key_exists('', $array);Configure your rector.php:
<?php
use Rector\Config\RectorConfig;
use Rector\Php85\Rector\FuncCall\ArrayKeyExistsNullToEmptyStringRector;
return RectorConfig::configure()
->withRules([
ArrayKeyExistsNullToEmptyStringRector::class,
]);
