Cannot modify readonly property

[deoomen]

PHP since version 8.1 supports readonly keyword to mark properties as non modifiable. But there is one problem. When an object has readonly props and it's passed to monolog, Redact will try to overwrite this property, but it's not possible so an exception will be thrown.

Maybe an option is to use reflection to create a clone of a not-readonly object and use that cloned object to overwrite props?

Quick example:

use Monolog\Handler\StreamHandler;
use RedactSensitive\RedactSensitiveProcessor;

class ReadonlyDTO
{
    public function __construct(
        public string $nonReadonlyProp1,
        public readonly string $readonlyProp1,
        public readonly string $readonlyProp2,
    ) {
    }
}

$obj = new ReadonlyDTO('nonreadonly', 'readonly', 'readonly');

$sensitive_keys = [
    'nonReadonlyProp1' => 4,
    'readonlyProp1' => 4,
];

$processor = new RedactSensitiveProcessor($sensitive_keys);

$logger = new \Monolog\Logger('Readme', [new StreamHandler(STDOUT)]);
$logger->pushProcessor($processor);

$logger->info('Hello, World!', ['obj' => $obj]);

Result:

PHP Fatal error:  Uncaught Error: Cannot modify readonly property ReadonlyDTO::$readonlyProp1 in /vendor/leocavalcante/redact-sensitive/src/RedactSensitiveProcessor.php:108