Why doesn't Valtio automatically track dependencies?

[transitive-bullshit]

During my deep-dive comparison of reactive TS frameworks, I was surprised to see that Valtio doesn't automatically track dependency reads in its computed properties or subscribe (which seems like the closest analog Valtio has to an effect).

#149 seems to have settled on a compromise by adding an optional watch to valtio/utils which at least makes dependency tracking possible, albeit with a somewhat awkward manual DX compared to other similar reactive libs (example which I may or may not have butchered 😂 ).

I know the authors of this project likely have a very good reason for this design decision, but I wasn't able to understand it by searching through the repo and old issues.

Related: #149 and potentially #82

I'd love to update my comparison with an explanation of how you guys think about automatic dependency tracking versus the more explicit approach taken by libs like Valtio and Jotai.

Thanks!

[dai-shi]

Because it's not the goal nor the scope. watch hasn't be actively improved lately and it may not provide dependency tracking mechanism. I think we need to overhaul watch to match your requirement (which sounds interesting).

fyi, the goal of valtio is to create immutable snapshots.

const p = proxy({ count: 1 });
const s1 = snapshot(p);
p.count = 2;
const s2 = snapshot(p);
// s1 should be { count: 1 } and s2 should be { count: 2 }

[transitive-bullshit]

Makes sense; thanks for the super quick reply, Daishi.

Would it be more accurate then to compare Valtio to Immer, as opposed to signals frameworks?

[dai-shi]

Yeah, that's what I was gonna say: Valtio is more comparable with Immer and ImmutableJS.

One of my old tweets: https://x.com/dai_shi/status/1330490462642192384

[transitive-bullshit]

Makes sense 🙏