Prompt #2 - Make Change

index.js

"use strict";

let currencyConfig = [{ "quarters": 25}, {"dimes": 10}, {"nickels": 5}, {"pennies": 1 }];

function configure(config) {
  currencyConfig = config;
}

function make_change(cents) {
  let change = {};
  let remaining = cents;

  for (var ix in currencyConfig) {
    let coin = currencyConfig[ix];
    let coinName = Object.keys(coin)[0];
    let coinValue = coin[coinName];

    if (remaining >= coinValue) {
      let numCoins = Math.floor(remaining / coinValue);

      change[coinName] = numCoins;
      remaining -= numCoins * coinValue;
    } else {
      delete change[coinName];
    }
  }

  return change;
}

module.exports = {
  make_change
};

test.js

"use strict";

var module = require("./index");

test("it returns 1 penny for 1 cent", () => {
  expect(module.make_change(1)).toEqual({ "pennies": 1 });
});

test("it returns 1 dime, 1 penny for 11 cents", () => {
  expect(module.make_change(11)).toEqual({ "dimes": 1, "pennies": 1 });
});

test("it returns 1 quarter, 1 dime, 1 nickel, and 2 pennies for 42 cents", () => {
  expect(module.make_change(42)).toEqual({ "quarters": 1, "dimes": 1, "nickels": 1, "pennies": 2 });
});