A plain `Map` strongly references every entry until you delete it.
Heap usage grows after repeated navigation, polling, subscriptions, cache writes, or background work. Use LRU, TTL, explicit invalidation, or WeakMap when appropriate.
Adding a cache without a size limit or expiry.
Remove long-lived references, clear timers/listeners, and verify the object can be collected.
const id = setInterval(tick, 1000); return () => clearInterval(id);
The visual proof is the active runtime event: watch what is retained, blocked, queued, or released at each step.
Repeat the workflow several times, take a heap snapshot, and confirm retained listeners, timers, or cached objects stop growing after cleanup.
Related cases
Continue with nearby confusion while the mental model is fresh.
interval leak
Clear polling intervals in React effects, widgets, and background refresh loops.
event listener leak
Clean up window, document, and shared element listeners in component lifecycles.
closure memory hold
Closures are useful for caches and private state, but can accidentally retain large objects.
Was this clear?
This stays local for now. It helps you track where the product still needs sharper cases.