Expected behavior

No memory leaks (Detached Elements)

Actual behavior

Memory leaks caused by select. Dispose not cleaning up properly

Resources (screenshots, code snippets etc.)

If I dont set private members to null the select Element does not get garbage collected:

oldSelect.dispose();

oldSelect._element = null;

oldSelect._activeOption = null;

oldSelect._plainOptions = null;

oldSelect._optionsToRender = null;

oldSelect._selectionModel = null;

There are also issues with MutationObserver. The method _disconnectMutationObserver is never called and it references an undefined variable:

this.mutationObserver instead of this._mutationObserver

_disconnectMutationObserver() {
    if (this.mutationObserver) {
      this._mutationObserver.disconnect();
      this._mutationObserver = null;
    }
  }