Strings with leading 0s are accepted but produce invalid JSON

[eug48]

i.e.

const bignumJSON = require('json-bignum')

> bignumJSON.stringify({key: new bignumJSON.BigNumber("0123")})
'{"key":0123}'

> JSON.parse(bignumJSON.stringify({key: new bignumJSON.BigNumber("0123")}))
SyntaxError: Unexpected number in JSON at position 8

I know the bug is mainly in the code using json-bignum but by allow invalid JSON to be produced the bug is allowed to propagate into other systems.. Perhaps strings with leading 0s should be rejected with an exception in the BigNumber constructor?

json-bignum/lib/bignumber.js

Line 11 in 68f270d

throw new Error(number + ' is not a number');

BTW, thanks very much for this simple & effective package.

[rpedela]

What does JSON.parse() and JSON.stringify() do in this case?

[eug48]

In Javascript syntax 0123 is treated as an octal constant, but 09123 throws an Error in Firefox but is converted to 9123 in Chrome & Node

[rpedela]

I think throwing an error is fine then. I would be happy to accept a PR. Thanks!