jest-leak-detector
Module for verifying whether an object has been garbage collected or not.
Internally creates a weak reference to the object, and forces garbage collection to happen. If the reference is gone, it meant no one else was pointing to the object.
Example
let reference = {};
const detector = new LeakDetector(reference);
// Reference is held in memory.
console.log(detector.isLeaked()); // true
// We destroy the only reference to the object.
reference = null;
// Reference is gone.
console.log(detector.isLeaked()); // false