minimum debounce.js

class Component extends React.Component {
  onScroll(event) {
    this.scrollPosition = getScrollPosition(event);
    if (this.scrolling) return;
    this.scrolling = true;
    
    const processLongOperation = (beginPosition) => {
      longOperation(beginPosition, (completionState) => {
        this.setState(completionState, () => {
          //rendered
          if (this.scrollPosition === beginPosition) {
             this.scrolling = false;
          } else {
            _.defer(processLongOperation, this.scrollPosition);
          }
        });
      });
    };
    
    processLongOperation(this.scrollPostion);
  }
}