Function buildTransitionSampleTimes

packages/cli/src/utils/layoutAudit.ts:264–292

({
  duration,
  boundaries,
  cap,
}: TransitionSampleOptions)

 * subset and `dropped` reports how many sample times were omitted.
 */
export function buildTransitionSampleTimes({
  duration,
  boundaries,
  cap,
}: TransitionSampleOptions): TransitionSamples {
  if (!Number.isFinite(duration) || duration <= 0) return { times: [], dropped: 0 };
  const inRange = uniqueSortedTimes(
    boundaries.filter((time) => Number.isFinite(time) && time >= 0 && time <= duration),
  );
  const withMidpoints = [...inRange];
  for (let i = 0; i < inRange.length - 1; i++) {
    const current = inRange[i];
    const next = inRange[i + 1];
    if (current === undefined || next === undefined) continue;
    withMidpoints.push(roundTime((current + next) / 2));
  }
  const merged = uniqueSortedTimes(withMidpoints);
  if (cap === undefined || merged.length <= Math.max(2, cap)) {
    return { times: merged, dropped: 0 };
  }
  const limit = Math.max(2, cap);
  const strided: number[] = [];
  for (let i = 0; i < limit; i++) {
    const pick = merged[Math.floor((i * (merged.length - 1)) / (limit - 1))];
    if (pick !== undefined) strided.push(pick);
  }
  const times = uniqueSortedTimes(strided);
  return { times, dropped: merged.length - times.length };
}

/** Merge sample-time lists into one deduplicated ascending list. */
export function mergeSampleTimes(...lists: number[][]): number[] {