Function eachMonthOfInterval

pkgs/core/src/eachMonthOfInterval/index.ts:59–89

(
  interval: IntervalType,
  options?: Options,
)

 * // ]
 */
export function eachMonthOfInterval<
  IntervalType extends Interval,
  Options extends EachMonthOfIntervalOptions | undefined = undefined,
>(
  interval: IntervalType,
  options?: Options,
): EachMonthOfIntervalResult<IntervalType, Options> {
  const { start, end } = normalizeInterval(options?.in, interval);

  let reversed = +start > +end;
  const endTime = reversed ? +start : +end;
  const date = reversed ? end : start;
  date.setHours(0, 0, 0, 0);
  date.setDate(1);

  let step = options?.step ?? 1;
  if (!step) return [];
  if (step < 0) {
    step = -step;
    reversed = !reversed;
  }

  const dates: EachMonthOfIntervalResult<IntervalType, Options> = [];

  while (+date <= endTime) {
    dates.push(constructFrom(start, date));
    date.setMonth(date.getMonth() + step);
  }

  return reversed ? dates.reverse() : dates;
}