Parsing an empty string succeeds and returns zero

[hdgarrood]

This appears to be by design in the underlying JavaScript library (emphasis mine):

You can create a bigInt by calling the bigInt function. You can pass in

• a string, which it will parse as an bigInt and throw an "Invalid integer" error if the parsing fails.
• a Javascript number, which it will parse as an bigInt and throw an "Invalid integer" error if the parsing fails.
• another bigInt.
• nothing, and it will return bigInt.zero.

The stage 3 draft BigInt specification for ES requires this too:

EDITOR'S NOTE
StringToBigInt("") is 0n according to the logic in 3.1.3.1.

This is not what I would do if it were up to me, but since this library is mostly just a binding to the underlying JavaScript library, perhaps the best way forward is to leave this as-is and clarify this behaviour in the documentation?

[sharkdp]

Thank you for the feedback. I agree with you. I would also rather have it return Nothing.

I'd be okay with changing this (and releasing a new major version).