React.memo native implementation (Polyfill)(Asked in Interview)

react.memo.js

const shallowCompare = (prev, next) => {  
  for (let key in next) {
    if (next[key] !== prev[key]) return false;
  }
  return true;
}; 
export function memo(Component, areEqual = shallowCompare) {  
  let prevProps = {};
  let prevResult = JSX.Element | undefined;
  return (nextProps) => {
    if (prevResult !== undefined && areEqual(prevProps, nextProps)) {
      return prevResult;
    }
    prevProps = nextProps;
    prevResult = <Component {...nextProps} />;
    return prevResult;
  }
}