Function removeKeyframeFromScript

packages/parsers/src/gsapParser.ts:2261–2323

(
  script: string,
  animationId: string,
  percentage: number,
)

 * remaining keyframe's properties.
 */
export function removeKeyframeFromScript(
  script: string,
  animationId: string,
  percentage: number,
): string {
  // Array-form keyframes (`keyframes: [{x,y}, …]`) have no explicit percentages —
  // GSAP distributes them evenly. The object-form path below can't see them
  // (findKeyframesObjectNode only matches ObjectExpression), so removing from an
  // array-form tween silently no-op'd. Resolve the element by its implicit
  // percentage and splice it; collapse to a flat tween when fewer than two remain.
  const arrLoc = locateAnimationWithFallback(script, animationId);
  // findPropertyNode here returns the property's VALUE node directly.
  const arrVal = arrLoc && findPropertyNode(arrLoc.target.call.varsArg, "keyframes");
  if (arrLoc && arrVal?.type === "ArrayExpression") {
    const elements: AstNode[] = (arrVal.elements ?? []).filter(
      (e: AstNode | null): e is AstNode => !!e && e.type === "ObjectExpression",
    );
    const n = elements.length;
    if (n === 0) return script;
    let matchIdx = -1;
    let bestDist = Number.POSITIVE_INFINITY;
    for (let i = 0; i < n; i++) {
      const pct = n > 1 ? (i / (n - 1)) * 100 : 0;
      const dist = Math.abs(pct - percentage);
      if (dist <= PCT_TOLERANCE && dist < bestDist) {
        matchIdx = i;
        bestDist = dist;
      }
    }
    if (matchIdx === -1) return script;
    const remaining = elements.filter((_, i) => i !== matchIdx);
    if (remaining.length < 2) {
      const sole = remaining[0];
      const record = sole ? objectExpressionToRecord(sole, arrLoc.parsed.scope) : {};
      collapseKeyframesToFlat(arrLoc.target.call.varsArg, record);
    } else {
      const realIdx = arrVal.elements.indexOf(elements[matchIdx]);
      arrVal.elements.splice(realIdx, 1);
    }
    return recast.print(arrLoc.parsed.ast).code;
  }

  const ctx = locateKeyframeCtx(script, animationId, percentage);
  if (!ctx) return script;
  const { loc, kfNode } = ctx;

  const match = findKeyframePropByPct(kfNode, percentage);
  if (!match) return script;
  const removeIdx = match.idx;

  kfNode.properties.splice(removeIdx, 1);

  const remainingKfs = filterPercentageProps(kfNode);
  if (remainingKfs.length < 2) {
    const record =
      remainingKfs.length === 1
        ? objectExpressionToRecord(remainingKfs[0]!.value, loc.parsed.scope)
        : {};