Number Formatters

number-formatters.ts

export const toFixedN = (
  number: number | null | undefined,
  fractionDigits = 8,
  canBeNull = true,
): string => {
  let num = number

  // @ts-ignore
  num = +num
  if (isNaN(num)) {
    return '-'
  }
  if (num === 0) {
    return canBeNull ? '0' : '~0'
  }
  if (num < 1) {
    // Cannot use parseFloat for small values due to exponential form
    // @ts-ignore
    num = num.toFixed(fractionDigits).replace(/\.0+$/, '').replace(/0+$/, '')
  } else {
    num = parseFloat(num.toFixed(fractionDigits))
  }
  // @ts-ignore
  return +num === 0 ? (canBeNull ? '0' : '~0') : num.toString()
}
              
const SI_SYMBOL = ['', 'k', 'M', 'B', 'T', 'q', 'Q']

export const abbreviateNumber = (
  number: number,
  params?: { fixed?: number },
) => {
  // if zero, we don't need a suffix
  // eslint-disable-next-line eqeqeq
  if (number == 0) {
    return '0'
  }
  if (number > -1 && number < 1) {
    return number
  }
  // what tier? (determines SI symbol)
  const tier = (Math.log10(Math.abs(number)) / 3) | 0
  // get suffix and determine scale
  const suffix = SI_SYMBOL[tier]
  const scale = Math.pow(10, tier * 3)
  // scale the number
  const scaled = number / scale
  // format number and add suffix
  return [
    typeof params?.fixed === 'number' ? toFixedN(scaled, params?.fixed || 0) : scaled,
    suffix,
  ].join('')
}