@nomicfoundation/ethereumjs-util/src/units.ts

A collection of utility functions for Ethereum

import { BIGINT_0, BIGINT_1 } from './constants.js'
/** Easy conversion from Gwei to wei */
export const GWEI_TO_WEI = BigInt(1000000000)

export function formatBigDecimal(
  numerator: bigint,
  denominator: bigint,
  maxDecimalFactor: bigint
): string {
  if (denominator === BIGINT_0) {
    denominator = BIGINT_1
  }

  const full = numerator / denominator
  const fraction = ((numerator - full * denominator) * maxDecimalFactor) / denominator

  // zeros to be added post decimal are number of zeros in maxDecimalFactor - number of digits in fraction
  const zerosPostDecimal = String(maxDecimalFactor).length - 1 - String(fraction).length
  return `${full}.${'0'.repeat(zerosPostDecimal)}${fraction}`
}