Polyfilled standard hooks

[dy]

useState(init?, deps?)

1. Normalizes initializer function (some hook providers have it not implemented).
2. Takes optional deps to reinitialize state.

function MyComponent(props) {
  // sets `currentValue` to `value` whenever passed `props.value` changes.
  let [currentValue, setCurrentValue] = useState(props.value, [props.value])
}

useEffect(fn, deps?)

1. Guarantees microtask - react/preact unpredictably call as microtask or sync.
2. No-deps useEffect(fn) is the same as empty-deps useEffect(fn, []).
   1. React's useEffect(fn) is equivalent to queueMicrotask(fn), which is redundant hook (principle 3).
   2. That is compatible with useState(initFn) (principle 2).
   3. Single-run useEffect(fn) is equivalent to useInit(fn)/useMount(fn) − that reduces cognitive load / lib size (principle 1).
3. Supports async functions.
4. Ignores non-functional returns.

function MyComponent(props) {
  let [result, setResult] = useState()

  // called once on init
  useEffect(async () => setResult(await load('/data')))

  // ...
}

Arguments against

That's matter of diversity vs unification.

• useEffect(() => () => {}) can be useful to destroy/reinit effect, that is not the same as queueMicrotask.
• useState() can be replaced with useMemo(calc, deps) to provide deps.
• useInit() is something closer to sync effect, rather than microtask.

[dy]

Ok, decided. Better split to useState and useEffect