Stanley-Yao

const mainReducer = combineReducers({a, b, c});

const secondReducer = function(state, action) {
    switch(action.type) {
        case SOME_ACTION:
            return someSpecificReducer(state.a, state.c);
        default: return state;    
    }
};

Stanley-Yao

import React, { useEffect, useRef, useState } from "react";

const AppBeta = () => {
  const [width, setWidth] = useState<number>(window.innerWidth);

  const [widgetBWidth, setWidgetBWidth] = useState<number | undefined>();

  const widgetBContainer = useRef<HTMLDivElement>(null);
  const updateWidth = () => {
    setWidth(window.innerWidth);

Stanley-Yao

import React, { useEffect, useState, useCallback } from "react";
import { useResizeDetector } from "react-resize-detector";
const AppGamma = () => {
  const [widthA, setWidthA] = useState<number>(800);

  const onResize = useCallback(() => {
    // on resize logic
  }, []);

  const { width, ref } = useResizeDetector({