memory-leak-audit

Replace raw addEventListener or .onclick assignments with addDisposableListener and register the result via this._register. For one-time lifecycle events, wrap the event with Event.once so the listener removes itself after the first invocation.

Use a MutableDisposable field registered once on the class, then assign the new listener to its .value inside the method. This guarantees at most one active listener no matter how many times the method runs, unlike calling this._register on every invocation.

Use Event.once for events that should fire only once, such as disposal, close, or first-change notifications. A regular subscription stays registered forever after firing, which leaks the listener and its captured references.

Call ensureNoDisposablesAreLeakedInTestSuite at the top of the test suite so leaked disposables fail the tests automatically. You can also compare listener counts before and after repeated operations to confirm counts stabilize.

Leak occurs when item listeners are registered to the pool class with this._register, so they are never cleaned per item. Create an item-scoped DisposableStore and return an object whose dispose method disposes that store.