Custom rounding modes

[jonasesr]

Currently there is no possibility to set up a custom rounding function. Therefore you are limited to the ones that are implemented by default. For my case I need a rounding function that always rounds up (e.g. 0.002 => 0.01 with precision 2, commercial rounding)

It would be nice to pass a callback or a string that describes the rounding mode. If it is a string and the string matches the supported ones, the matching function gets executed. If it is a callback, the callback gets executed.

[sarahdayan]

Hi @jonasesr! I'm totally open to a PR that implements this 🙂

This will be done like that in v2, but if you need it now, feel free.

[sarahdayan]

Hey there! I just released Dinero.js v2 in alpha, and you no longer need to pass a rounding function when performing mutations.

You can still pass a rounding mode when formatting with toUnit or toFormat, and the library provides rounding functions for convenience. You can pass your own if you want to.

import { dinero, toUnit } from 'dinero.js';
import { USD } from '@dinero.js/currencies';

const d = dinero({ amount: 10555, currency: USD, scale: 3 });

toUnit(d, { digits: 1, round: Math.round }); // 10.6
toUnit(d, { digits: 1, round: Math.floor }); // 10.5
toUnit(d, { digits: 2, round: Math.trunc }); // 10.55

You can see it in action here.