Function handleReplaceWithKeyframes

packages/sdk/src/engine/mutate.ts:933–966

(
  parsed: ParsedDocument,
  op: Extract<EditOp, { type: "replaceWithKeyframes" }>,
)

}

function handleReplaceWithKeyframes(
  parsed: ParsedDocument,
  op: Extract<EditOp, { type: "replaceWithKeyframes" }>,
): MutationResult {
  const script = getGsapScript(parsed.document);
  if (!script) throw new Error("No GSAP script block found in the composition.");
  if (op.keyframes.length === 0) return EMPTY;
  // #11: tween IDs are position-derived and re-point after any structural edit,
  // so a stale `animationId` can resolve to a DIFFERENT tween. Require the
  // located animation to still target the selector the caller expects; if it is
  // absent or now points at another element, bail rather than silently replace
  // the wrong tween. (validateOp's gsapAnimationMissing only catches absent ids.)
  const located = locateGsapAnimation(parsed, op.animationId);
  if (!located || located.animation.targetSelector !== op.targetSelector) return EMPTY;
  // Step 1: remove the existing tween. Position-derived IDs renumber, so the
  // inverse patch restores the full GSAP script rather than trying to re-insert
  // by ID (handled by the coarse gsapScriptChange patch pair).
  const afterRemove = removeAnimationFromScript(script, op.animationId);
  // Defense in depth: if the id resolved to nothing the script is unchanged —
  // bail rather than degrade the replace into a plain add (duplicate tween).
  if (afterRemove === script) return EMPTY;
  // Step 2: insert the replacement keyframed tween.
  const { script: newScript, id: animationId } = addAnimationWithKeyframesToScript(
    afterRemove,
    op.targetSelector,
    op.position,
    op.duration,
    op.keyframes,
    op.ease,
  );
  if (!animationId) return EMPTY;
  setGsapScript(parsed.document, newScript);
  return { ...gsapScriptChange(script, newScript), meta: { animationId } };
}

// ─── setClassStyle handler ────────────────────────────────────────────────────