[🐞] Signals don't trigger rerender with some problematic JSX markup

[EatChangmyeong]

Which component is affected?

Qwik Runtime

Describe the bug

I was randomly writing some edge case code (orphaned signals in this case) to see what happens when I first encountered this bug. Trying to reproduce the bug in the playground later revealed that this bug depends on the returned JSX markup.

In the following reproduction, app.tsx exports two components V1 and V2, which have different JSX markup (V1's children are nested in extra p's) but are otherwise the same.

Expected behavior: apart from the visual differences (from not having extra p's), both components should show the same behavior, that is:

• clicking on ++ and -- buttons should always increment and decrement the counter (both parent's and child's), and
• the counter should reset to zero whenever Child rerendering triggers its useTask$.

Actual behavior: Once V2's Child unmounts for the first time, the parent counter gets stuck and no longer updates. V1 does not show this behavior and works as expected.

Reproduction

https://qwik.builder.io/playground/#v=1.4.2&f=5Va9DoIwEN55ClwICWAENgKdfATD7oA4kGA0xoH03b3eHW1BEkEdSFz4aa%2FXu%2B%2B7PztoklT7Y0dNaNovfmJhY%2BpoeU5cEQ5lDChMhhbtY3mvrnumrjBX%2BzswuBeDijnYGx6zBc%2Ftg0q3LX46NrcKpfqAZmAuBkscckxv78hSuHgLiX%2Bv6BlFUkSRHon4cDeSksuUBoEUQTBUqpJsrom9y6QNHN%2BMlqQ4tHXdVK92j456npsTemBiodySEFHkDlsEsUTJP%2BI5WTXPn7M7ze03zP6YxgUkMneOQxj2%2BNm0dUiBzJA6%2BMw443N%2B0YwnBKiZJHiCWT1yg3IaoM1Zl1Z8uAll8U4NAOtUGyri7HbU8R4j8789KYlT41kZhyoTjTVraU3QBnRnUr%2FJ%2B0b1BA

Steps to reproduce

No response

System Info

System:
    OS: Linux 4.14 Arch Linux ARM
    CPU: (8) arm64 Cortex-A55
    Memory: 860.85 MB / 3.58 GB
    Container: Yes
    Shell: 5.2.21 - /bin/bash
  Binaries:
    Node: 20.10.0 - /usr/sbin/node
    npm: 10.3.0 - /usr/sbin/npm
  npmPackages:
    @builder.io/qwik: ^1.3.5 => 1.4.2
    @builder.io/qwik-city: ^1.3.5 => 1.4.2
    undici: * => 6.5.0
    vite: ^5.0.11 => 5.0.12

Additional Information

No response

[wmertens]

Thank you for the repro, that indeed looks like a bug.

[JerryWu1234]

Let me take a look.
It would be great if you could offer a clue that off the top of your head about this bug.

[wmertens]

Since we have v2 well underway and it rebuilds some of this code, let's wait until we can test this with v2 alpha.

[aarbi]

Also I want to point out another related issue with the example app we get after running pnpm create qwik and choosing the Basic App starter, the counter there is broken and can reproduced quickly by running pnpm preview, hitting the "+" button makes the number drops from 70 to 50

[gioboa]

I did a double check with the latest v2 code and it's working fine.
v2 will be release soon so I marked this issue with STATUS-3: solved by V2, thanks.