Roman Numerals converter

gistfile1.txt

const romanNumeral = (char, val) => {
  return {
    char: char,
    val: val,
    isBellow: comp => comp > val,
    isAbove: comp => comp < val,
    is: comp => comp === val,
    times: repeat => {
      return (new Array(parseInt(repeat))).fill(char).join('')
    }
  }
}
const NUMERALS = [
  romanNumeral('I', 1),
  romanNumeral('V', 5),
  romanNumeral('X', 10),
  romanNumeral('L', 50),
  romanNumeral('C', 100),
  romanNumeral('D', 500),
  romanNumeral('M', 1000)
]

const lastItemInArray = arr => arr[arr.length - 1]

const LARGEST_NUMERAL = lastItemInArray(NUMERALS)

const extractDigits = numeric => {
  let rem = 10
  let digits = 0
  while(digits == 0) {
    digits = numeric % rem
    rem *= 10
  }
  return digits
}
  
const convert = numeric => {
  const digitsToConvert = extractDigits(numeric)
  const nextVal = numeric - digitsToConvert
  
  let result = false
  
  let indexOfNextNumeral = NUMERALS.findIndex(numeral => numeral.isAbove(digitsToConvert))
  if(indexOfNextNumeral === undefined) {
    //above 1000
    return LARGEST_NUMERAL.times(LARGEST_NUMERAL.val/digitsToConvert)
  } else {
    const NEXT_NUMERAL = NUMERALS[indexOfNextNumeral]
    let index = 0
    while(index < indexOfNextNumeral && !result) {
      if(NUMERALS[index].val === digitsToConvert)
      {
        result = NUMERALS[index].char
      } else if(NEXT_NUMERAL.val - NUMERALS[index].val === digitsToConvert) {
        result = NUMERALS[index].char + NEXT_NUMERAL.char
      } else if(index + 1 === indexOfNextNumeral) {
        if(index === 0) {
          result = NUMERALS[index].times(digitsToConvert)
        } else if(digitsToConvert % NUMERALS[index].val === 0) {
          result = NUMERALS[index].times(digitsToConvert/NUMERALS[index].val)
        } else {
          result = NUMERALS[index].char + NUMERALS[index - 1].times(Math.abs(digitsToConvert - NUMERALS[index].val) / NUMERALS[index - 1].val)
        }
      } 
      index++
    }
  }
  
  return nextVal > 0 ? convert(nextVal) + result : result
}

console.log(convert(265))