uasort() with 'strnatcasecmp' acts weird

[staabm]

Description

we are in the process of covering the handling of uasort when using with strnatcasecmp and found a few things which we are not able to make sense of. I also looked thru the docs and did not find something which explained what we see.

the problem occur arround strict-types and Stringable vs. string territory.

especially interessting is that strnatcasecmp when invoked directly behaves differently in comparison while using strnatcasecmp as callback via uasort. results vary with strict-types 0/1.

see

• https://3v4l.org/XgFEm#v8.3.30 (no error without declare)
• https://3v4l.org/slZeW#v8.3.30 (strnatcasecmp error with declare strict=1)
• https://3v4l.org/TdBcf#v8.3.30 (uasort doesn't error with declare strict=1)
• https://3v4l.org/AAlUE#v8.3.30 (uasort via arrow-fn using strnatcasecmp())

so our questions mainly are

• is all this expected behaviour?
• can someone share some insights so we can properly reflect php-src runtime behaviour in PHPStan?

thank you

PHP Version

PHP 8.3.x

Operating System

No response

[TimWolla]

declare(strict_types=1) only affects calls made by functions that are defined in the file having the declare. All engine-defined functions, including uasort() behave as if they were defined in a file without declare(strict_types=1) and thus parameters are coerced when uasort() calls the callback.