How would you fix a memory leak in your code…

Would identify the source of the leak using browser developer tools (Timeline / Performance, Memory).

Common causes of memory leaks:

Dangling object references:
- Forgotten timers (setInterval, setTimeout) referencing objects.
- Undetached event handlers (removeEventListener).
- Closures holding external variables longer than necessary.
- DOM elements removed from the document but still referenced in JavaScript.

// Example of a leak due to a forgotten timer
const leakyObject = {
  data: 'some data'
};

setInterval(() => {
  console.log(leakyObject.data); // leakyObject cannot be garbage collected
}, 1000);

Large data structures:
- Creating and storing excessively large arrays or objects when iterators or streaming could suffice.
Incorrect cache usage:
- Caches that grow infinitely without eviction strategies (LRU, LFU, etc.).
Leaks from third-party libraries:
- Check the documentation or source code of libraries for potential issues.

Fixes:

Cancel events and timers: Ensure all event handlers are detached and timers cleared when destroying a component or object.

// Proper timer cleanup
const leakyObject = {
  data: 'some data'
};
let timerId;

function startTimer() {
  timerId = setInterval(() => {
    console.log(leakyObject.data);
  }, 1000);
}

function stopTimer() {
  clearInterval(timerId); // Clear the timer
}

Nullify references: Explicitly nullify references to large or unused objects so the garbage collector can reclaim them.
Use WeakMap and WeakSet: To store references to objects that can be garbage collected when no other strong references exist.
Optimize data structures: Use more efficient data structures or approaches (e.g., lazy loading).
Limit cache size: Implement eviction strategies for caches.
Update or replace libraries: If the issue is in a third-party library, update it or find an alternative.

After fixing, use developer tools again to confirm the leak is resolved.

How would you fix a memory leak in your code?