Handling Memory Leaks in React Native with Event Listeners During Production Deployment
I'm optimizing some code but Currently developing a cross-platform mobile application using React Native and facing challenges with memory utilization. After profiling the app, it seems that event listeners are not being removed properly, leading to significant memory leaks. Here's the scenario: in my component, I'm adding an event listener for a real-time data feed that updates the UI. However, even after the component unmounts, the listener remains active, consuming resources. I've tried using the `componentWillUnmount` lifecycle method to clean up the listeners, but it doesn't seem to be effective. Here’s the relevant snippet: ```javascript componentDidMount() { this.dataFeedListener = DataFeed.on('data', this.updateData); } componentWillUnmount() { DataFeed.off('data', this.updateData); } ``` Despite these attempts, when I run a memory profiling tool, the memory usage continues to increase steadily after navigating away from this component. I've also explored using `useEffect` in functional components, but that hasn't resolved the issue either: ```javascript useEffect(() => { const listener = DataFeed.on('data', updateData); return () => { DataFeed.off('data', listener); }; }, []); ``` I suspect that there might be another part of the code maintaining a reference to the old listener, but debugging has been tough. Any insights on how to ensure that these listeners are cleaned up correctly or alternative strategies for managing subscriptions in a React Native environment? A deep dive into best practices for event handling in production apps would be particularly helpful.