What modern JavaScript feature is being combined with WeakMap in this code?
const finalizationRegistry = new FinalizationRegistry(key => {
// Cleanup when object is garbage collected
});
const weakMap = new WeakMap();
function register(obj, metadata) {
weakMap.set(obj, metadata);
finalizationRegistry.register(obj, 'key');
}
This code combines WeakMap with FinalizationRegistry: 1) FinalizationRegistry provides notifications when objects are garbage collected, 2) This allows for cleanup actions when WeakMap entries are removed, 3) The combination enables tracking of when weak references are cleared, 4) This is useful for resource cleanup and monitoring, 5) FinalizationRegistry is a modern addition to complement weak reference features, 6) The pattern allows for more sophisticated memory management strategies, 7) It enables cleanup of related resources when objects are collected, 8) This demonstrates advanced memory management capabilities in modern JavaScript.