Why not use BigInt now native to node.js since v10.4.0?

[codyzu]

Since v8 added native BigInt support and that has been available since node.js v10.4.0, why not use that instead of bignumber.js?

Thanks for this package! Greate work!

[huturen]

@codyzu it has the problems that JSON.stringify a BigInt value as of v10.4.0

> theBiggestInt = 9007199254740991n;
9007199254740991n

> JSON.stringify(theBiggestInt)
Thrown:
TypeError: Do not know how to serialize a BigInt
    at JSON.stringify (<anonymous>)

[rramaa]

@huturen BigInt's toJSON is not implemented. I think that it can be handled using by implementing the BigInt.prototype.toJSON function.

But it would also override the default behavior of BigInt!

[mnpenner]

@huturen But we wouldn't be using JSON.stringify, we'd be using JSONbig.stringify and they handle it.

@rramaa No need to override to prototype either.

if(typeof x === 'bigint') {
    return String(x);
}