symfony/ux-css slow on big array shape
Author: staabmCreated Oct 1, 2026Updated Oct 1, 2026
Labelsperformance
Bug report
The array shape that symfony/ux-css generates for its css() Twig function has about 840 keys, 126 of them referring to a nested shape, and checking one method parameter against it took seconds.
reproducer in https://github.com/Kocal/sf-ux-css-phpstan-reproducer
running the reproducer on PHPStan 2.2.16:
➜ sf-ux-css-phpstan-reproducer git:(main) ✗ vendor/bin/phpstan analyse -c phpstan-nested.neon --debug -vv
Result cache not used because of debug mode.
/Users/staabm/workspace/sf-ux-css-phpstan-reproducer/src/Ui/Button.php
Result cache is saved.
[OK] No errors
Elapsed time: 31.34 seconds
Peak memory: 78 MBrunning the reproducer on PHPStan 2.3.x@bee10c5:
➜ sf-ux-css-phpstan-reproducer git:(main) ✗ vendor/bin/phpstan analyse -c phpstan-nested.neon --debug -vv
Result cache not used because of debug mode.
/Users/staabm/workspace/sf-ux-css-phpstan-reproducer/src/Ui/Button.php
Result cache is saved.
[OK] No errors
Elapsed time: 4.76 seconds
Peak memory: 54 MBSource: phpstan/phpstan