rescript-use-sync-external-store

This is a zero-cost ReScript binding to use-sync-external-store. Specifically to use-sync-external-store/shim.

Usage

See __test__/SyncExternalStore_test.res for usage.

Migration from use-subscription

If you were using rescript-use-subscription before, migration should be fairly straightforward:

Before

1let {useSubscription} = module(UseSubscription)
2
3@react.component
4let make = () => {
5  let options = React.useMemo(() => {
6    UseSubscription.getCurrentValue: () => Some(1),
7    subscribe: callback => {
8      callback(. Some(1))
9
10      (.) => ()
11    },
12  })
13  let val = useSubscription(options)
14
15  <div>{val->Belt.Option.mapWithDefault(React.null, React.int)}</div>
16}

After

1let val = ref(Some(1))
2
3@react.component
4let make = () => {
5  let val = SyncExternalStore.use(
6    ~getSnapshot=() => val.contents,
7    ~subscribe=callback => {
8      callback()
9      () => ()
10    },
11    (),
12  )
13
14  <div> {val->Belt.Option.mapWithDefault(React.null, React.int)} </div>
15}