@restate/core/build/create-selector-hook.js

_Restate_ is a predictable, easy to use, easy to integrate, typesafe state container for [React](https://reactjs.org/).

import { useContext, useEffect, useMemo, useState } from "react";
import { BehaviorSubject } from "rxjs";
import { distinctUntilChanged } from "rxjs/operators";
const identitySelectorFunction = (state) => state;
function createSelectorHook(context, outerSelector = identitySelectorFunction) {
  function useAppState(selector, props) {
    const _store = useContext(context);
    const _props = {
      deps: [],
      compare: void 0,
      ...props
    };
    const state = _store.state;
    const deps = _props.deps;
    const startValue = useMemo(
      () => getSelectedValue(state, outerSelector, selector),
      [...deps]
    );
    const [value, setValue] = useState(startValue);
    const output$ = useMemo(() => {
      return new BehaviorSubject(startValue);
    }, [state]);
    useEffect(() => {
      const stateSub = _store.state$.subscribe((nextStateValue) => {
        const nextValue = getSelectedValue(
          nextStateValue.state,
          outerSelector,
          selector
        );
        output$.next(nextValue);
      });
      const outputSub = output$.pipe(distinctUntilChanged()).subscribe((nextStateValue) => setValue(nextStateValue));
      return function cleanup() {
        stateSub.unsubscribe();
        outputSub.unsubscribe();
      };
    }, [output$, ...deps]);
    return value;
  }
  return useAppState;
}
function getSelectedValue(state, outerSelector, selector) {
  const subState = outerSelector(state);
  const value = selector(subState);
  return value;
}
export {
  createSelectorHook
};