[🐞] V2 regression -> useVisibleTask$ runs before render commit when a prior task mutates a tracked signal, breaking imperative DOM access

[maiieul]

Which component is affected?

Qwik Runtime

Describe the bug

See reproduction.

Reproduction

https://qwikdev-build-v2.qwik-8nx.pages.dev/playground/#f=7ZdNb9NAEIb%2FyrSg2pEiIwQXrDiopVAJaC1SKuAWp1kXCzcJ2YQqiiJx4caRI%2Fy5%2FBLe2Zk46yaVqFBvvVnez3nn45mttSJPn2yLmuYav%2B7Tr2%2F%2F2aeIOIVNR6iJyfqckKsmLria8XVqxjMu0VNbmxYU%2FdIE3kSUv3%2BZJmjrmNyf1npZGs7KdoiZmApOsY20H1NeFiNLXblol7IcVAX3ARfGDXh6WZwzA%2B2XSBYeD1EdrQxz25PRu85byjQOTXQRMbpQbFAuhhcPG6BCNqHLKVMIyxQJvNl1oEgpXUtIijzFXaS4YBt4UK4coVgBQwnlWWkNj3C%2BejYeUHhwdnT0qRFzR2XGKHhAzmF6jDufG2vVrFOD26kMidurSz2DjgGIQ%2FlW%2FjOdi0mT7FAd53qF4ViD3jpWbbMtnGtLtfDME4%2BhMeIIccMaQL5pK2tzTnIzaOhR8ld2AD4T4Esqb1S7WBg8kIiQGCE%2F3irpsP45BbnrMpa%2FfwQUU3CSvqdX6dnJIS3%2F%2FETQb%2Bj6gsIPaefNfocnQVwxL%2BM4JW5y%2BogiJ93r0484wcWfas081M5Awu%2BKGwdHwB6AYVXxvImBAoTuzTjXigECDnt%2BRlabgZWtJF55vriGlt9%2FsXf4jx4KNSkrr7IZGguEEP9x500YzePpwEXALfzl1Pa9VaXchsN2TFn3V5XElfYq%2Bzc0rawcy%2B%2BJffNrZ9Su%2BTmmljwr2vMNDy9aj3SMgbbeAOfFq5LKf1YbXLvk1uXznVr67e2521HRT3ZFjl02J5lX2iza2nRLJpm%2BvLoWG6%2Bzm3H7%2BJn3oLwNbmsF%2FB62dwHbvw

Steps to reproduce

No response

System Info

⚡️

Additional Information

No response

[maiieul]

Not sure if this should be considered a bug but it's definitely a regression. It used to work in v1. The better pattern is to use a ref so if we can't fix it we need to add it to the v2 migration steps.

[wmertens]

Hmm, so the signal change causes NODE_DIFF and then the visible task runs before the cursor completes.

This may be a bug @Varixo, what do you think? Maybe dirty visible tasks should be logged while cursor walking and can only run once the walk is flushed, in top-down order?