BofA Money Input: Parse & Format Functions

moneyParseFormat.js

const format = num =>
  (num / 100).toLocaleString("en-US", { style: "currency", currency: "USD" })
const parse = str => +str.replace(/[^0-9.]/, "") * 100

const rEFormat = num => {
  const formattedNum =
    num.toString().length < 3
      ? `000${num.toString()}`.slice(-3)
      : num.toString()
  return `$${formattedNum
    .replace(/([0-9]{2})$/, ".$1")
    .replace(/\B(?=(\d{3})+(?=\.))/g, ",")}`
}
const rEParse = str => +str.replace(/[^0-9]/g, "").replace(/^0*(\d+)/, "$1")

const tests = [
  { input: 0, expects: "$0.00" },
  { input: 3, expects: "$0.03" },
  { input: 30, expects: "$0.30" },
  { input: 300, expects: "$3.00" },
  { input: 300000, expects: "$3,000.00" }
]

const handle = num => rEFormat(num)
const render = str => rEParse(str)

tests.forEach(test =>
  console.log(
    test.expects === handle(test.input) && test.input === render(test.expects)
  )
)