Roman numbers in JS

roman.js

const roman = (n) => {
    const div = (v, d) => {
        return {quotient: v / d, rest: v % d}
    };

    const romanMap = [
        {diviser: 1000, letter: "M"},
        {diviser: 900, letter: "CM"},
        {diviser: 500, letter: "D"},
        {diviser: 400, letter: "CD"},
        {diviser: 100, letter: "C"},
        {diviser: 90, letter: "XC"},
        {diviser: 50, letter: "L"},
        {diviser: 40, letter: "XL"},
        {diviser: 10, letter: "X"},
        {diviser: 9, letter: "IX"},
        {diviser: 5, letter: "V"},
        {diviser: 4, letter: "IV"},
        {diviser: 1, letter: "I"},
    ];
    const {tempResult: result} = romanMap.reduce(
        ({rest: tempRest, tempResult}, {diviser, letter}) => {
        const {quotient, rest} = div(tempRest, diviser);
        return {
            rest,
            tempResult: tempResult + letter.repeat(quotient),
        }
    }, {rest: n, tempResult: ''});

    return result;
};

console.log(roman(4));
console.log(roman(3));
console.log(roman(9));
console.log(roman(12));
console.log(roman(69));
console.log(roman(22));
console.log(roman(16));
console.log(roman(2569));