`transaction_submitAndWatch`: consider returning "index" as integer, not string

[jsdw]

Just a small thing for consideration; events like "finalized" look like:

{
    "event": "finalized",
    "block": {
        "hash": "0x...",
        "index": "2"
    }
}

The "index" is a string, not a number. Given that we never expect indexes to be particularly huge (certainly not outside what JS can interpret as a number), should we just return the integer instead?

Consistency is a reason for doing so, eg with this event on the same subscription, numPeers is an integer, not a string:

{
    "event": "broadcasted",
    "numPeers": ...
}

What's your preference?

[josepot]

I completely agree that it makes total sense for the value of this JSON field to be a number, rather than a string. Absolutely!

certainly not outside what JS can interpret as a number

However, I would like to clarify that in some cases it could be useful to pass numbers that can potentially be very large as strings, so that in JS we can use BigInt to parse those large numbers. For instance, we could use this custom JSON.parse:

const bigIntJsonParse = (input: string) =>
  JSON.parse(input, (_, value) =>
    !isNaN(value) && !Number.isSafeInteger(+value) ? BigInt(value) : value,
  )

I've actually used this in the past 🙂

This would be completely unnecessary in this case, of course. I just wanted to clarify that since BigInts were introduced into the ECMAScript spec, it's now possible for JS to handle large numbers, even when they are passed through JSON values (as long as they are passed as strings and the consumer knows how to interpret those, of course).