Simple currency formatter

currencyFormat.js

function formatCurrency(number) {
  const [integerPart, decimalPart] = `${number}`.split(".");
  const chunkSize = 3;
  const integerPartArray = integerPart.split("").reverse();
  const chunks = Math.ceil(integerPartArray.length / chunkSize);
  const formatedInteger = Array.from(new Array(chunks), (_, idx) => {
    return integerPartArray
      .slice(idx * chunkSize, idx * chunkSize + chunkSize)
      .reverse()
      .join("");
  }).reverse();
  return `${formatedInteger.join(",")}.${decimalPart}`;
}
// TODO: document