Can't perform a React state update on an unmounted component - TwoGears/hakomo-guides GitHub Wiki

If you try to change the state of a component, but the component has already been unmounted, this will throw error due to memory leak.

to avoid that, keep a variable that tracks mounted state and update the state only if it is mounted:

export default function Comp(props){
   let mounted = useRef(true);
   useEffect(()=>{
      
      //  If your effect returns a function, React will run it when it is time to clean up
      return ()=>{
          mounted.current = false;
      }
   ,[]}
   async function handleClick(){
      if(mounted.current){
        // set state.
      }
   }
}