signal created fromStore with a derived loses reactivity

[leonidaz]

Describe the bug

When you use a fromStore and a derived from it, the signal created with fromStore loses reactivity.

It looks like, the compilation is different (JS Output tab).

with derived:

const count = fromStore(countStore);

without derived defined:

const count = $.mutable_state(fromStore(countStore));

Reproduction

Reproduction

Try commenting out the derived and the counter works

Logs

No response

System Info

playground

Severity

annoyance

[7nik]

Because the fromStore isn't a recursive proxy. So, like with the stores, you should re-assign the value:

-<button onclick={() => count.current.n++}>click</button>
+<button onclick={() => count.current = { n: count.current.n + 1 }}>click</button>

Though this nuance should be noted in the docs.

---

Try commenting out the derived and the counter works

By doing so, you go to the legacy mode. If you migrate that code, the reactivity doesn't work again.

[leonidaz]

By doing so, you go to the legacy mode. If you migrate that code, the reactivity doesn't work again.

Ah, 🤦‍♂️ I totally missed that it was switching modes on me. I wish I could just set the runes mode in the playground and it would stay that way. Yeah, I recall now that I have to set the whole fromStore. Yeah, definitely needs more documentation 😄

@7nik thank you!