Vanilla subscribe does not trigger when a computed getter is updated

[sharathprabhal]

I use Valtio as a store for in a project that uses both React and vanilla. I have a keyed object of items in a store. Based on user action, I set a "derived" currentObject and use a getter to select "current object" and perform operations on it. When the "current object" is updated, useSnapshot triggers but subscribe does not.

See repro code at https://codesandbox.io/s/valtio-subscribe-57p4st

Please let me know if this is a bug or if there is a alternate/better way to do this. Thanks!

[dai-shi]

It's how JS works:

subscribe(store.currentObject, () => ...)

// ☝️ that means the following 👇 

const objectAtTheFirstTime = store.currentObject
subscribe(objectAtTheFirstTime, () => ...)

You should subscribe to the store: subscribe(store, () => ...)

[sharathprabhal]

thanks, @dai-shi . Do you have any recommendations for what I'm trying to achieve, which is essentially trying to listen to changes for a "selector" ? without having to re-subscribe every time the object changes.

[dai-shi]

let lastObjectSnap
subscribe(store, () => {
  const currentObjectSnap = snapshot(store.currentObject);
  if (lastObjectSnap !== currentObjectSnap) {
    lastObjectSnap = currentObjectSnap
    // do your stuff
  }
})

[sharathprabhal]

Thank you!