Function handleAddGsapTween

packages/sdk/src/engine/mutate.ts:1026–1065

(
  parsed: ParsedDocument,
  target: HfId,
  tween: GsapTweenSpec,
)

// fallow-ignore-next-line complexity
function handleAddGsapTween(
  parsed: ParsedDocument,
  target: HfId,
  tween: GsapTweenSpec,
): MutationResult {
  const script = getGsapScript(parsed.document);
  if (!script) throw new Error("No GSAP script block found in the composition.");

  const extras: Record<string, unknown> = {};
  if (tween.repeat !== undefined) extras.repeat = tween.repeat;
  if (tween.yoyo !== undefined) extras.yoyo = tween.yoyo;
  if (tween.stagger !== undefined) extras.stagger = tween.stagger;

  // A fromTo's destination may arrive as either `toProperties` or `properties`
  // (the Studio add path sets `properties`). Fall back the same way for every
  // method — the old fromTo-only branch read `toProperties` alone and wrote an
  // empty to-vars object, so fromTo animations added via cutover animated to {}.
  const toProps = (tween.toProperties ?? tween.properties ?? {}) as Record<string, number | string>;

  // Scoped ids like "hf-host/hf-leaf" must use the bare leaf id in the GSAP
  // selector — only the leaf part is written as data-hf-id on the DOM element.
  const bareTarget = target.includes("/") ? (target.split("/").at(-1) ?? target) : target;
  const animation: Omit<GsapAnimation, "id"> = {
    targetSelector: gsapTargetSelector(parsed.document, bareTarget),
    method: tween.method,
    position: tween.position ?? 0,
    ...(tween.duration !== undefined ? { duration: tween.duration } : {}),
    ...(tween.ease ? { ease: tween.ease } : {}),
    properties: toProps,
    ...(tween.fromProperties
      ? { fromProperties: tween.fromProperties as Record<string, number | string> }
      : {}),
    ...(Object.keys(extras).length > 0 ? { extras } : {}),
  };

  const { script: newScript, id: animationId } = addAnimationToScript(script, animation);
  if (!animationId) return EMPTY;
  setGsapScript(parsed.document, newScript);
  return { ...gsapScriptChange(script, newScript), meta: { animationId } };
}

// fallow-ignore-next-line complexity
function handleSetGsapTween(