React useEffect not cleaning up event listeners after component unmounts
I've been banging my head against this for hours. I'm having an issue with my React component where I set up an event listener within a `useEffect` hook, but it doesn't seem to be cleaning up properly when the component unmounts. I'm using React 17.0.2 and here's a simplified version of my code: ```javascript import React, { useEffect, useState } from 'react'; function MyComponent() { const [data, setData] = useState(null); useEffect(() => { const handleResize = () => { console.log('Window resized'); }; window.addEventListener('resize', handleResize); return () => { console.log('Cleaning up...'); window.removeEventListener('resize', handleResize); }; }, []); return <div>{data}</div>; } export default MyComponent; ``` Even though I see the 'Cleaning up...' message in the console when I unmount the component, I still notice that after the component is removed, the event listener still seems to be firing. I checked that the component isn't kept in memory, and Iām not using any external state management libraries which could be interfering. I've tried changing how I define `handleResize` by moving it outside the `useEffect`, but that didn't help. I also confirmed that the unmounting is indeed happening by logging a message in a second `useEffect` that runs when the component is about to unmount. The React dev tools show that the component is unmounted, yet I still see the 'Window resized' log in the console when I resize the window. Am I missing something? Is there a specific caveat in React 17 with clean-ups or event listeners that I should be aware of? Any help would be greatly appreciated! I'd really appreciate any guidance on this.