Simple durations stringifier for Moment.js

StringifyDuration.js

/**
 * Simple durations stringifier for Moment.js
 *  Return a human readable string representing the given moment duration
 *  Based on @cogwirrel comment (https://github.com/moment/moment/issues/348#issuecomment-346233713)
 *
 * TODO:
 *  - Add simple lang support (fr, en)
 */

function stringifyDuration (duration) {
  // Simple implementation of https://lodash.com/docs#dropWhile
  const dropWhile = (arr, fn) => arr.slice(arr.findIndex(v => !fn(v)))

  // Split the duration into parts, and drop the most significant parts with a value of 0
  const durationParts = dropWhile([
    { value: duration.years(), unit: 'an' },
    { value: duration.months(), unit: 'mois', iv: true }, // if the unit is invariable
    { value: duration.days(), unit: 'jour' },
    { value: duration.hours(), unit: 'heure' },
    { value: duration.minutes(), unit: 'minute' },
    { value: duration.seconds(), unit: 'seconde' },
    { value: duration.milliseconds(), unit: 'milliseconde' }
  ], (part) => part.value === 0)

  // Display up to two of the most significant remaining parts
  return durationParts.slice(0, 2).map((part) => (
    `${part.value} ${part.unit + (!part.iv && part.value > 1 ? 's' : '')}`
  )).join(', ')
}

stringifyDuration(moment.duration(26, 'hours')) // => "1 day, 2 hours"

/**
 * [JS Standard](https://standardjs.com/demo.html?gist=022f86e1cfbf65b7ef7ecae1d3ee980c)
 */