Feature request: Add information about smallest coin value Currency

[OhGhie4iew]

The smallest coin value currently available in SEK is 0.50 SEK.
So in some cases it makes sense to display 1.37 SEK as 1.50 SEK

To produce correct results when rounding it would make sense that the Currency objects also contains information about the smallest coin value.

[sarahdayan]

Hey @OhGhie4iew!

Can you walk me through some use cases so I fully understand the problem space?

One of the main goals of Dinero.js is to separate data from its final representation. If you want never to display decimal values other than 0.0 and 0.5, you can do this when formatting with toFormat. This way, you preserve the data integrity and accuracy within the object, and respect the reality of SEK when displaying.

import { dinero, toFormat } from 'dinero.js';
import { SEK } from '@dinero.js/currencies';

const d = dinero({ amount: 525, currency: SEK });

toFormat(d, ({ amount, currency }) => {
  if (amount % 0.5 === 0 || amount % 0.5 === 0) {
    return `${currency.code} ${amount}`;
  }

  return // your rounding logic;
});