store value is not displayed after update when created via toStore()

[leonidaz]

Describe the bug

Displaying the value of the store, created via toStore() doesn't work.

Reading the value of the store immediately after creation properly shows the store value in the template but not via console.log()

Reproduction

Link to Playground:

• The printed value of the $store in the template remains 0
• Console logging the value of the $store after store updates still shows 0
• Button click increment via the store sets the value to 1 ($store remains at 0)

Logs

No response

System Info

Svelte Playground 5.1.4

Severity

annoyance

[trueadm]

Reading the store in the component will show stale values, that's because toStore uses an effect to sync the values and effects run after a microtask. There does seem to be an issue why the store in the template doesn't work right though.

[leonidaz]

Reading the store in the component will show stale values, that's because toStore uses an effect to sync the values and effects run after a microtask.

right, it's confusing though since toStore() implies that it creates a real store. The real store behavior, i.e. writable(), behaves differently and any updates to it are immediately available.

[trueadm]

@leonidaz It does create a real store – except signals and observables work differently, and in this case an effect is used to capture the latest value and sync it back to the store.