[🐞] Weird behavior when accessing props value in differents way

[Wykks]

Which component is affected?

Qwik Optimizer (rust)

Describe the bug

I'm not sure how to describe it best, when accessing a value from a props in a specific way, Qwik behave differently on update, which in some case can crash the app if not expected.

Reproduction

https://stackblitz.com/edit/qwik-starter-usz5pr?file=src%2Froutes%2Fmy-stuff-modal.tsx

Steps to reproduce

See comments in repro

System Info

System:
    OS: Linux 5.0 undefined
    CPU: (8) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
    Memory: 0 Bytes / 0 Bytes
    Shell: 1.0 - /bin/jsh
  Binaries:
    Node: 18.18.0 - /usr/local/bin/node
    Yarn: 1.22.19 - /usr/local/bin/yarn
    npm: 10.2.3 - /usr/local/bin/npm
    pnpm: 8.15.3 - /usr/local/bin/pnpm
  npmPackages:
    @builder.io/qwik: 1.5.2 => 1.5.2 
    @builder.io/qwik-city: 1.5.2 => 1.5.2 
    undici: 5.28.2 => 5.28.2 
    vite: 4.5.2 => 4.5.2

Additional Information

No response

[wmertens]

can you explain exactly what errors you're getting? Also, try updating qwik-ui

[Wykks]

If you open the modal then close it (click or esc key), there's this error (and then the app doesn't work anymore) :

props.stuff is undefined MyStuffModalContent_component_fooSig_useComputed_sBXmoQdQVq

stuff is set to undefined like this :

onClose$={() => {
    stuffSig.value = undefined;
}

But this should not happen, because the modal component should be destroyed before being updated.

The weird part is that when reading stuff like this :

const foo = props.stuff.foo;
return <div>{foo.foo2}</div>;

It doesn't work (props.stuff is undefined on modal close).

But this doesn't throw any errors :

const stuff = props.stuff;
return <div>{stuff.foo.foo2}</div>;

Also the first case const foo = props.stuff.foo; works if directly written in the main modal component.

This is a very short repro, it doesn't seems a big deal, bug with more code and more complicated models this can be hard to debug (at least for me, as I'm still not used to debug Qwik... quickly 😅 )

(Also qwik-ui updated, no changes)

[Wykks]

@PatrickJS Can you elaborate a bit why this is "not planned" ? 😅
I believe this is a important issue in Qwik. Quite easy to workaround, but not that easy to debug. I spent hours to identify the bug and make that reproduction, I could have spend more hours to narrow it more but closing this like that is not motivating...