chainId as bigint

[nftchance]

Hello, I have been working around signed types/messages and have run into quite a perplexing situation. Right now, the declaration of TypedDataDomain is:

export type TypedDataDomain = {
  chainId?: number | undefined
  name?: string | undefined
  salt?: ResolvedRegister['BytesType']['outputs'] | undefined
  verifyingContract?: Address | undefined
  version?: string | undefined
}

This is fine in most cases as there are not currently any chains with a large chainId, however I think there may be a case to treat it as a uint256 like specified in EIP-712

Right now, if you are working with signed types you will inevitably find yourself needing to declare the domain type like:

export const EIP712_TYPES = {
	EIP712Domain: [
		{ name: 'name', type: 'string' },
		{ name: 'version', type: 'string' },
		{ name: 'chainId', type: 'uint256' },
		{ name: 'verifyingContract', type: 'address' },
		{ name: 'salt', type: 'bytes32' }
	]
} as const

Again, we are still fine here. However, as you can see, chainId is a uint256 which means it should "really" be a bigint (I think) like here https://github.com/wagmi-dev/abitype/blob/00dd694139d995a98b8994ed180e60bcbc5e2947/packages/abitype/src/utils.ts#L66-L75.

I have been working on a library that automatically builds my entire stack, but domain here has sent me down a rabbit hole after building everything around the declared TypedDataDomain. It's a uint256, so I get a bigint as my expected type in one piece, but then when it comes to signing my data, it expects a number. Obviously, I could just do as bigint but this is spread everywhere throughout my codebase and is in multiple points: the database, API, etc.

Thoughts? I saw it was updated in this commit originally, so maybe I am missing something?

In the end, I got past it with a super hacky fix, but still wonder why that was needed and if this is an issue others have experienced?

Is the expected fix to override the export as is suggested here?

[Raiden1411]

I believe that this was specific to something in wagmi but i was not around when this was changed, so I cant really help. @tmm any thoughts?