Calling ReflectionClass::isSubclassOf() multiple times doesn't narrow types correctly in 8.4

Open dktapps opened this issue 1 month ago • 1 comments

Bug report

The result is correct up to 8.3, but *NEVER* in 8.4 for some reason.

Code snippet that reproduces the problem

https://phpstan.org/r/52a81990-cb4a-4e1b-b638-c5f9b39a5688

Expected output

The same output on all PHP versions

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Nov 10 '25 20:11 dktapps

TypeSpecifying is here https://github.com/phpstan/phpstan-src/blob/e870ac104cdf2b6ce67aed0d6e7e1f5cbce9b07f/src/Type/Php/ReflectionClassIsSubclassOfTypeSpecifyingExtension.php#L20

One thing to know is the fact that the ReflectionClass stub change in PHP 8.4 https://github.com/phpstan/phpstan-src/blob/e870ac104cdf2b6ce67aed0d6e7e1f5cbce9b07f/src/PhpDoc/ReflectionClassStubFilesExtension.php#L9

Template type is not covariant anymore https://github.com/phpstan/phpstan-src/blob/e870ac104cdf2b6ce67aed0d6e7e1f5cbce9b07f/stubs/ReflectionClass.stub#L6 vs https://github.com/phpstan/phpstan-src/blob/e870ac104cdf2b6ce67aed0d6e7e1f5cbce9b07f/stubs/ReflectionClassWithLazyObjects.stub#L6

Maybe it imply some fix on TypeSpecifyingExtension side...

Nov 11 '25 15:11 VincentLanglet