Function trackEnterClasses

packages/core/src/animation/utils.ts:73–89

(
  el: HTMLElement,
  classList: string[],
  cleanupFns: VoidFunction[],
)

 * added to properly remove them when the longest animation fires.
 */
export function trackEnterClasses(
  el: HTMLElement,
  classList: string[],
  cleanupFns: VoidFunction[],
) {
  const elementData = enterClassMap.get(el);
  if (elementData) {
    for (const klass of classList) {
      elementData.classList.push(klass);
    }
    for (const fn of cleanupFns) {
      elementData.cleanupFns.push(fn);
    }
  } else {
    enterClassMap.set(el, {classList, cleanupFns});
  }
}

/**
 * Helper function to cleanup enterClassMap data safely