luxon time ago string

time-ago.ts

import { DateTime } from 'luxon';

const units: Intl.RelativeTimeFormatUnit[] = ['year', 'month', 'week', 'day', 'hour', 'minute', 'second'];

/**
 * https://github.com/moment/luxon/issues/274#issuecomment-649347238
 *
 * @param dateTime DateTime.fromISO(isoString)
 * @returns string
 *
 * @example
 * ```ts
 * timeAgo(DateTime.fromISO(publish_date_time)) // -> 19 hours ago
 * ```
 */
export const timeAgo = (dateTime: DateTime) => {
  const diff = dateTime.diffNow().shiftTo(...units);
  const unit = units.find((unit) => diff.get(unit) !== 0) || 'second';

  const relativeFormatter = new Intl.RelativeTimeFormat('en', {
    numeric: 'auto',
  });
  return relativeFormatter.format(Math.trunc(diff.as(unit)), unit);
};