Synthetische Ereignisweiterleitung und MutationObserver-Mocking beim Testen von Svelte-Knoten-Direktiven

export function testSvelteAction(actionFn, targetNode, options) {
  const mutations = [];
  const mockObserver = new MutationObserver((records) => mutations.push(...records));
  mockObserver.observe(targetNode, { attributes: true, childList: true });
 
  const instance = actionFn(targetNode, options);
  targetNode.dispatchEvent(new CustomEvent('test-trigger', { bubbles: true }));
 
  return {
    getMutations: () => [...mutations],
    cleanup: () => {
      mockObserver.disconnect();
      instance?.destroy?.();
    }
  };
}