A couple of days ago news got out that Firefox will be getting support for BigInt in Firefox 68. This is great news for everyone who likes really large numbers.

My current job is in finance, and the workarounds for dealing with big integers in browsers have been a bit frustrating.

A few months ago I set off to build a Javascript/Typescript library to do fixed-point financial math, called bigint-money. Soon this means that I can start using this not just server-side, but also in browsers. To celebrate, I just released version 1.0.

Since my last blogpost, the following features were added:

1. Before all rounding was done using ‘Bankers Rounding’ a.k.a. ‘round half to odd’, but since then support has been added for other rounding methods such as ‘half away from 0’, ‘half towards 0’ and ‘truncate’.
2. New comparison functions: isLesserThan(), isGreaterThan(), isEqual(), isLesserThanOrEqual(), isGreaterThanOrEqual(). All of this could be done before with the compare() function, but these functions will make your source a lot easier to read.
3. More precision. In the past I picked an arbitrary maximum precision of 12 decimals, because it felt like this should be enough for any currencies I could find. Since then I actually ran into cases where I needed more. ERC-20 and Ethereum actually use up to 18 decimals. The new default is a precision of 20 decimals.
4. abs() and sign() methods, contributed by flacktack, which behave similar to Math.abs() and Math.sign().

If you’re interested, check out the project on Github.