Extract FilterFunctionReturnTypeHelper

[herndlm]

First step to support the same (crazy, but apparently working) logic via filter_input() too.

[ondrejmirtes]

How do you expect this helper to be called for filter_input? What's the difference between filter_var and filter_input? Thank you.

[herndlm]

the core logic is the same, filter_var() expects a single mixed var as input, while filter_input() expects an input type (GET/POST/..) and a var name (which would be the array key on the input super global). Additionally filter_input handles the case when the var name offset is not existing at all on the superglobal input array.

https://www.php.net/manual/en/function.filter-var.php vs https://www.php.net/manual/en/function.filter-input.php

See https://github.com/phpstan/phpstan-src/pull/2010/files#diff-8d424599365db1271856abb9d8444194e495d7eebcd0894d0e05dc04d871a6ae for planned usage

[ondrejmirtes]

Thank you 😊