[1.x] Fix running phpstan with newer PHP versions (e.g. 8.4)

[n-peugnet]

Changes proposed in this pull request:

phpstan 1.8 cannot run properly with PHP 8.4, but newer versions in the 1.x branch do, thus we change the requirement to phpstan ^1.9, to allow version up to 2.0 (excluding).

Newer phpstan versions now detect common errors in regexes:

Ignored error #Template type T of function resolve[()]{2} is not referenced in a parameter.# has an unescaped '()' which leads to ignoring all errors. Use '\(\)' instead.
Ignored error #^Unsafe usage of new static[()]{2}.$# has an unescaped '()' which leads to ignoring all errors. Use '\(\)' instead.

So these regexes are also fixed by using non-evaluated string literals and escaping the parenthesis as recommended instead of using a weird trick with the brackets.

Reviewers should focus on:

???

Screenshot

Before:

After:

Necessity

• Has the problem that is being solved here been clearly explained?
• If applicable, have various options for solving this problem been considered?
• For core PRs, does this need to be in core, or could it be in an extension?
• Are we willing to maintain this for years / potentially forever?

Confirmed

• Frontend changes: tested on a local Flarum installation.
• Backend changes: tests are green (run composer test).
• Core developer confirmed locally this works as intended.
• Tests have been added, or are not appropriate here.

[imorland]

Thank you for this @n-peugnet. I've not ran this locally yet, but yes I think this will probably work out!

Can you please rebase this, and target the 1.x branch 🙏

[n-peugnet]

@imorland: just rebased, sorry I didn't find this 1.x branch and thought that main was the version 1 branch.

[imorland]

Thank you for this PR @n-peugnet! I've tested the changes locally with PHP 8.4 and unfortunately discovered a compatibility issue that prevents us from merging this.

The Problem

While PHPStan 1.9+ works perfectly with PHP 8.4, it's incompatible with the version of Larastan we're using. Specifically:

• Flarum 1.x uses Laravel 8 (illuminate packages ^8.0)
• Laravel 8 requires Larastan 1.x (both nunomaduro/larastan and larastan/larastan)
• Larastan 1.x only supports PHPStan ^1.0 <1.9 due to breaking API changes in PHPStan 1.9

When running PHPStan 1.9+ with Larastan 1.x, we get this error:

Internal error: Too few arguments to function PHPStan\Analyser\MutatingScope::assignVariable(), 
2 passed in vendor/nunomaduro/larastan/src/ReturnTypes/CollectionFilterDynamicReturnTypeExtension.php 
on line 96 and at least 3 expected

Testing

I confirmed that:

• ✅ PHPStan 1.12.32 runs successfully on PHP 8.4 when Larastan is disabled
• ❌ PHPStan 1.9+ crashes when Larastan is enabled due to API incompatibility

Path Forward

For Flarum 1.x, we'll need to keep PHPStan pinned to >=1.8.11 < 1.9.0. Static analysis can continue running on PHP ≤8.3 while production code runs on PHP 8.4+.

This should be revisited for Flarum 2.x when we upgrade to Laravel 10+, which will allow us to use Larastan 2.x with PHPStan 1.9+.

I think the only option is to close this PR for now, but I really appreciate you taking the time to investigate and submit this fix! 🙏

[n-peugnet]

I understand, then what about setting >=1.8.11 < 2.0 instead and let users of larastan use the version 1.0.4 that specifies phpstan ^1.0 <1.9?

This would allow extension developers that do not use larastan to still use phpstan with PHP >= 8.4, and users of larastan to still be able to use it with PHP < 8.4.

[imorland]

Thanks again for digging into this @n-peugnet — genuinely appreciated.

Unfortunately this can't land on 1.x. flarum/phpstan hard-requires nunomaduro/larastan: ^1.0, and Larastan 1.x only supports PHPStan ^1.0 <1.9. So even with >=1.8.11 <2.0, Composer will always resolve PHPStan back down to <1.9 to satisfy Larastan — which means PHP 8.4 still ends up on a PHPStan 1.8.x that can't run there. The only way around it would be decoupling Larastan from flarum/phpstan, which isn't something we want to take on for 1.x (security-maintenance only).

The good news: this is already resolved on 2.x, which uses phpstan/phpstan: ^2.1 + larastan/larastan: ^3.8 and runs fine on PHP 8.4.

Closing as wontfix for 1.x. Thanks again for the thorough investigation!