Fix types after ctype_digit() with casted parameter

[staabm]

closes phpstan/phpstan#8736

[ondrejmirtes]

Can you please explain the changes and your findings since the last PR?

[staabm]

as can be seen in https://3v4l.org/k3Qce casting the parameter for ctype-digit to int beforehand does not yield a usefull result at all.

therefore I adjusted the extension to only narrow on (string) call.

I think its not worth to add logic into the extension which turns all "bad uses" of casted parameters into a NeverType.

[ondrejmirtes]

phpstan/phpstan#8736 is about (string) cast, not (int) cast, so please explain what changes for (string) that makes 1.9.13 not work.

[staabm]

in 1.9.13 we assumed a parameter type before casting would be the same as the one the ctype_digit function narrows.

this is not entirely correct. you can actually pass in e.g. a 1 which casted to string is a numeric-string, but is not contained within the

phpstan-src/src/Type/Php/CtypeDigitFunctionTypeSpecifyingExtension.php

Lines 47 to 57 in a6a3441

	$types = [
	IntegerRangeType::fromInterval(48, 57), // ASCII-codes for 0-9
	IntegerRangeType::createAllGreaterThanOrEqualTo(256), // Starting from 256 ints are interpreted as strings
	];
	if ($context->true()) {
	$types[] = new IntersectionType([
	new StringType(),
	new AccessoryNumericStringType(),
	]);
	}

type.

what we actually need is a type which represents all values which after casted with (string) will lead in a numeric-string. thats also the reason why e.g. bool is narrowed to true

[staabm]

with this change, I just turn the narrowing for non-string casts back to what it was before the recent PR #2186

[phpstan-bot]

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[phpstan-bot]

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[ondrejmirtes]

Thank you.