jeongtae

import React from "react";
import { ExampleProvider } from "./ExampleContext";
import MyComponent from "./MyComponent";

/** uses: `<MultipleProvider providers={[FirstProvider, SecondProvider, ...]}>` */
const MultipleProvider = ({ providers = [], children }) => {
  const reducer = (previous, provider) => React.createElement(provider, { children: previous });
  const reduced = providers.reduce(reducer, children);
  return reduced;
};

jeongtae

import { useEffect, useRef } from 'react';

function usePrevious<T>(value: T): T | undefined {
  const ref = useRef<T>();
  useEffect(() => {
    ref.current = value;
  }, [value]);
  return ref.current;
}