Überprüfung der MutationObserver-Lebenszyklusbereinigung in benutzerdefinierten Elementdirektiven

export function observeAttributeChanges(node, callback) {
  const observer = new MutationObserver((mutations) => callback(mutations));
  observer.observe(node, { attributes: true });
  return {
    destroy() {
      observer.disconnect();
    }
  };
}
 
export async function testActionCleanup(nodeMock) {
  let called = false;
  const action = observeAttributeChanges(nodeMock, () => { called = true; });
  action.destroy();
  await Promise.resolve();
  return called === false;
}