monval

Precise and simple money utility with exchange rates support.

monval uses Gaussian rounding when exporting values in a fixed length. Currently, the gaussian method is the only supported rounding method but the module flexible enough to provide more rounding methods in future releases.

Install

npm i monval

Import

There are exports for es6, cjs and umd environments:

// cjs
const {monval} = require('monval')

// es
import {monval} from 'monval'

// script tag, window.monval
<script src="https://cdn.jsdelivr.net/npm/monval@2/dist/monval.iife.js" type="text/javascript"></script>

Usage

// start with ten dollars in a pocket
const account = monval.create(10, 'USD')

// incoming 100.789$
account.add(100.789)

// 21.66$ spent!
account.subtract(21.66)

// 10 percent increase!
account.add('%10')

// 20 percent discount!
account.subtract('%20')

// The value always stored as float.
assert.strictEqual(account.toFloat(), 78.43352)
// toFixed method rounds the value according to the rounding algorithm and
// the decimal length standart to the currency
assert.strictEqual(account.toFixed(), '78.43')

// pretty print
monval.create(123.4567, 'EUR').pretty() // € 123.46
monval.create(123.4567, 'EUR').pretty(4) // € 123.4567

Let's load exchange rates:

const sampleExchangeRates = {/* EUR: 0.99, TRY: 1.11 ... */}
monval.exchangeRatesBaseCurrency = 'USD'
monval.exchangeRates = sampleExchangeRates.rates

// convert our usd to try
account.exchange('TRY')
// the pocket now has
assert.strictEqual(account.toFloat(), 478.16211132800004)
// turkish liras
assert.strictEqual(account.money.currency, 'TRY')

account.pretty() // ₺ 478.16

// add more dollars into the pocket!
account.add(100, 'usd')
// now we have 1087.8 try!
assert.strictEqual(acount.toFixed(), '1087.8')

Additional features:

monval.isCurrency('XXX') // false
monval.isCurrency('EUR') // true

Contributing

If you're interested in contributing, read the CONTRIBUTING.md first, please.

Version management of this repository done by releaser 🚀

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