Convert Number to Words

{
  "key": "number-to-words",
  "name": "Number to Words",
  "description": "Convert a number into words",
	"developerEmail": "email@bryter.io",
  "parameters": [
    {
      "name": "Number",
      "type": "number",
      "description": "The number to convert"
    }
  ],
  "result": {
    "type": "text",
    "description": "The number as words"
  }
}

function main(numberToConvert: number) {

    const MAX_SAFE_INTEGER = 9007199254740991

    function isSafeNumber(value: number) {
        return typeof value === 'number' && Math.abs(value) <= MAX_SAFE_INTEGER
    }

    function isFinite(value: number) {
        return !(typeof value !== 'number' || value !== value || value === Infinity || value === -Infinity)
    }

    const TEN = 10
    const ONE_HUNDRED = 100
    const ONE_THOUSAND = 1000
    const ONE_MILLION = 1000000
    const ONE_BILLION = 1000000000 //         1.000.000.000 (9)
    const ONE_TRILLION = 1000000000000 //     1.000.000.000.000 (12)
    const ONE_QUADRILLION = 1000000000000000 // 1.000.000.000.000.000 (15)
    const MAX = 9007199254740992 // 9.007.199.254.740.992 (15)

    const LESS_THAN_TWENTY = [
        'zero',
        'one',
        'two',
        'three',
        'four',
        'five',
        'six',
        'seven',
        'eight',
        'nine',
        'ten',
        'eleven',
        'twelve',
        'thirteen',
        'fourteen',
        'fifteen',
        'sixteen',
        'seventeen',
        'eighteen',
        'nineteen',
    ]

    const TENTHS_LESS_THAN_HUNDRED = [
        'zero',
        'ten',
        'twenty',
        'thirty',
        'forty',
        'fifty',
        'sixty',
        'seventy',
        'eighty',
        'ninety',
    ]

    function toWords(number: number) {
        let num = number;

        if (typeof number != 'number') {
            num = parseInt(number, 10)
        }

        if (!isFinite(num)) {
            return new TypeError(`Not a finite number: ${number} (${typeof number})`)
        }
        if (!isSafeNumber(num)) {
            return new RangeError(`Input is not a safe number, it's either too large or too small.`)
        }

        const words = generateWords(num)
        return words
    }

    function generateWords(number: number, words?: string[]): string {
        let word = '';
        let remainder = 0;

        // We're done
        if (number === 0) {
            return !words ? 'zero' : words.join(' ').replace(/,$/, '')
        }
        // First run
        if (!words) {
            words = []
        }
        // If negative, prepend "minus"
        if (number < 0) {
            words.push('minus')
            number = Math.abs(number)
        }

        if (number < 20) {
            remainder = 0
            word = LESS_THAN_TWENTY[number]
        } else if (number < ONE_HUNDRED) {
            remainder = number % TEN
            word = TENTHS_LESS_THAN_HUNDRED[Math.floor(number / TEN)]
            // In case of remainder, we need to handle it here to be able to add the "-"
            if (remainder) {
                word += '-' + LESS_THAN_TWENTY[remainder]
                remainder = 0
            }
        } else if (number < ONE_THOUSAND) {
            remainder = number % ONE_HUNDRED
            word = generateWords(Math.floor(number / ONE_HUNDRED)) + ' hundred'
        } else if (number < ONE_MILLION) {
            remainder = number % ONE_THOUSAND
            word = generateWords(Math.floor(number / ONE_THOUSAND)) + ' thousand,'
        } else if (number < ONE_BILLION) {
            remainder = number % ONE_MILLION
            word = generateWords(Math.floor(number / ONE_MILLION)) + ' million,'
        } else if (number < ONE_TRILLION) {
            remainder = number % ONE_BILLION
            word = generateWords(Math.floor(number / ONE_BILLION)) + ' billion,'
        } else if (number < ONE_QUADRILLION) {
            remainder = number % ONE_TRILLION
            word = generateWords(Math.floor(number / ONE_TRILLION)) + ' trillion,'
        } else if (number <= MAX) {
            remainder = number % ONE_QUADRILLION
            word = generateWords(Math.floor(number / ONE_QUADRILLION)) + ' quadrillion,'
        }

        words.push(word)
        return generateWords(remainder, words)
    }

    return toWords(numberToConvert);
};