The "precision" option handles both precision for storage and for formatting

[marknorrapscm]

Ideally we would have an option for precision that is used for calculations and a separate option for formatting. For example, you may want a precision of 4, but then want to display only 2 decimal places. Here's an example:

The math:

0.555 * 3 = 1.665

And in code:

currency("0.555", { precision: 4 }).multiply(3).format()

This outputs 1.6650 as expected

currency("0.555", { precision: 2 }).multiply(3).format()

This outputs 1.68

The second output of 1.68 is correct when calculating with a precision of 2 but is otherwise mathematically false. There is no option (that I can see) to retain the precision of 4 under the hood and then have the library produce a rounded string value by calling .format() (the correct rounded value in this case being 1.67).

Of course, you could parse it yourself and do the rounding, but this is added work that the library could handle.

I haven't been using this package for long so apologies if this has been covered elsewhere (or if I'm just plain wrong); I checked the closed issues and didn't see this mentioned. Is it possible to achieve what I want using the existing currency.js?

[scurker]

This is now possible in v2 with custom formatters.

import currency from 'currency.js'

const format = c => c.value.toFixed(2)
const c1 = value => currency(value, { precision: 3, format })

c1(1.234).value // 1.234
c1(1.234).format() // => "1.23"