Handling Memory Leaks in React with useEffect Hook on Component Unmount
I tried several approaches but none seem to work. I'm working with issues with memory leaks in my React application when components unmount. I'm using the `useEffect` hook to set up subscriptions to an API, but after navigating away from the component, the subscription seems to continue running, leading to unexpected behavior and errors. Here's the relevant portion of my code: ```javascript import React, { useEffect, useState } from 'react'; const DataFetcher = () => { const [data, setData] = useState(null); useEffect(() => { const subscription = apiService.subscribeToData((newData) => { setData(newData); }); return () => { subscription.unsubscribe(); }; }, []); return <div>{data ? JSON.stringify(data) : 'Loading...'}</div>; }; ``` Despite calling `unsubscribe` in the cleanup function, I still notice multiple subscriptions when the component is re-mounted. Additionally, the console logs show warnings about state updates on unmounted components. I'm using React v17.0.2. I've also tried moving the subscription logic within a separate function, but the scenario continues. What am I missing here? How can I ensure that the subscription is properly cleaned up to avoid memory leaks? For context: I'm using Javascript on Windows. Is there a better approach? This is part of a larger web app I'm building.