Crash / Infinite loop when target class constructor accepts self

[mpesari]

Hi, stumbled into this:

<?php declare(strict_types=1);

require_once __DIR__ . '/vendor/autoload.php';

class Test {
    public function __construct(string|self $value) {
        // copy-constructor-ish
    }
}

$mapper = (new CuyZ\Valinor\MapperBuilder)->mapper();

$test = $mapper->map(Test::class, ['value' => 'foo']); // string -> OK

$test = $mapper->map(Test::class, ['value' => $test]); // self -> OK

$test = $mapper->map(Test::class, ['value' => null]); // null -> FAIL

$ php test.php
PHP Fatal error:  Uncaught Error: Xdebug has detected a possible infinite loop, and aborted your script ...

Without Xdebug it just keeps running.

[kevariable]

you'd need string | self | null

[mpesari]

Let me clarify:

What is expected to happen?

Because null is not allowed as $value, the mapper is expected to throw MappingError.

This is what happens if self is removed from allowed types:

Uncaught CuyZ\Valinor\Mapper\TypeTreeMapperError: Could not map type `Test`. An error occurred at path value: Value null is not a valid string.

What actually happens?

The library enters infinite loop/recursion.

Program crashes when either time limit or memory limit is reached.