Method formatToParts

src/duration-format-ponyfill.ts:98–127

(duration: Duration)

  }

  formatToParts(duration: Duration): DurationPart[] {
    const list: string[] = []
    const options = this.#options
    const style = options.style
    const locale = options.locale
    for (const [unit, nfUnit] of partsTable) {
      const value = duration[unit]
      if (options[`${unit}Display`] === 'auto' && !value) continue
      const unitStyle = options[unit]
      const nfOpts =
        unitStyle === '2-digit'
          ? twoDigitFormatOptions
          : unitStyle === 'numeric'
          ? {}
          : {style: 'unit' as const, unit: nfUnit, unitDisplay: unitStyle}

      let formattedValue = new Intl.NumberFormat(locale, nfOpts).format(value)

      // Custom handling for narrow month formatting to use "mo" instead of "m"
      if (unit === 'months' && (unitStyle === 'narrow' || (style === 'narrow' && formattedValue.endsWith('m')))) {
        formattedValue = formattedValue.replace(/(\d+)m$/, '$1mo')
      }

      list.push(formattedValue)
    }
    return new ListFormat(locale, {
      type: 'unit',
      style: style === 'digital' ? 'short' : style,
    }).formatToParts(list)
  }

  format(duration: Duration) {
    return this.formatToParts(duration)