`rememberPossiblyImpureFunctionValues: false` + `max()` = false positive

[LastDragon-ru]

Bug report

You need to set rememberPossiblyImpureFunctionValues: false and phpstan will report about error. Please not that max(0, $number) works fine, but max(0, HelloWorld::getNumber()) not.

Code snippet that reproduces the problem

https://phpstan.org/r/9a0bea76-ab41-4d2e-bea0-d3bad33c3b41

Actual output

 ------ ---------------------------------------------------------------------------------------------- 
  Line   bug.php                                                                                       
 ------ ----------------------------------------------------------------------------------------------
  21     Parameter #1 $number of static method HelloWorld::sayHello() expects int<0, max>, int given.
 ------ ----------------------------------------------------------------------------------------------

Expected output

no errors

[VincentLanglet]

The MinMaxFunctionReturnTypeExtension is rewriting

max($a, $b);

to

$a < $b ? $b : $a;

Maybe that's the issue here,

max(0, HelloWorld::getNumber())

is changed to

0 < HelloWorld::getNumber() ? HelloWorld::getNumber() : 0;

which does allow PHPStan to restrict to int<0, max> because of rememberPossiblyImpureFunctionValues: false.

[VincentLanglet]

This can be reproduced with a /** @phpstan-impure */ phpdoc
https://phpstan.org/r/5f17418d-762c-4b85-9b44-abb9e250d866
and has been solved by phpstan/phpstan-src#3928

There is already a similar non-regression test, should we close this or do you want an extra non regression test @ondrejmirtes ?