Add `NoDiscard` attribute on mutation free methods

[Baptouuuu]

https://wiki.php.net/rfc/marking_return_value_as_important

[raman976]

Hello ,please assign me this issue. I want to work on this.

[raman976]

@Baptouuuu
Hi! I noticed that the issue asks to add the #[\NoDiscard] attribute to mutation-free methods.
However, since the project targets PHP 8.2 and #[\NoDiscard] is only available in PHP 8.4+, I wanted to clarify:

Should I define a custom NoDiscard attribute for now?

Or is there a plan to upgrade the minimum PHP version to 8.4 soon?

Happy to proceed either way — just wanted to confirm before making changes. Thanks!

[Baptouuuu]

NoDiscard will be available in PHP 8.5 this november. But since it's an attribute it should be possible to already use it, it willl simply do nothing yet.

The minimum PHP requirement should not be changed for this. Attributes are supposed to be backward compatible.

If for some reason we are forced to upgrade then I prefer for PHP 8.5 to be released before doing this change.

[Baptouuuu]

Despite Psalm complaining, adding the attribute seems fine Innmind/LogReader#10.