PHP 8.1 Readonly property cannot have a default value

[sofyco]

Bug report

PHPStan with PHP 8.1 shows an error when you use the default value for a read-only property in the constructor.

https://wiki.php.net/rfc/readonly_properties_v2

As the property has no default value, the assignment in the constructor is initializing, and thus legal. The constructor property promotion feature was specifically designed for forward-compatibility with readonly properties.

Code snippet that reproduces the problem

final class ErrorResponse
{
    public function __construct(public readonly string $message, public readonly array $parameters = [])
    {
    }
}

has error:

Readonly property cannot have a default value.

Expected output

No errors should be detected.

[mergeable]

This bug report is missing a link to reproduction on phpstan.org.

It will most likely be closed after manual review.

[simPod]

Link p.org https://phpstan.org/r/cd3f48eb-865d-43d5-8cf9-ca4e1c47d04d

[ondrejmirtes]

Fixed: phpstan/phpstan-src@7c8e81d

[sofyco]

@ondrejmirtes Thank you!!!

[github-actions]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.