react-use/docs/useMountedState.md

useMountedState

NOTE!: despite having State in its name this hook does not cause component re-render.
This component designed to be used to avoid state updates on unmounted components.

Lifecycle hook providing ability to check component's mount state.
Returns a function that will return true if component mounted and false otherwise.

Usage

import * as React from 'react';
import {useMountedState} from 'react-use';

const Demo = () => {
  const isMounted = useMountedState();

  React.useEffect(() => {
    setTimeout(() => {
      if (isMounted()) {
        // ...
      } else {
        // ...
      }
    }, 1000);
  });
};