@leverj/adapter/src/MathUtil.js

common utilities used in leverj exchange

const affirm    = require('@leverj/affirm')
const BigNumber = require('bignumber.js')

module.exports = function () {
  const mathUtil = {}

  mathUtil.toBN = function (number, decimalPlaces) {
    affirm(decimalPlaces === 0 || decimalPlaces, 'decimal places must be provided')
    affirm(typeof number === 'number', 'Invalid number')
    affirm(typeof decimalPlaces === 'number' && decimalPlaces >= 0 && decimalPlaces <= 18, 'invalid decimalPlaces')
    const multiplied = BigNumber(number).shiftedBy(decimalPlaces)
    return multiplied.integerValue(BigNumber.ROUND_DOWN)
  }
  return mathUtil
}()