[Balance] useBalance Viem symbol parsing error propagation (string -> bytes32)

[odcey]

Check existing issues

• I checked there isn't already an issue for the bug I encountered.

Describe the bug

Reading the MKR balance on Ethereum is not possible
getBalance is trying to read symbol as a string instead of bytes32

Apparently there's a catch handling this here: https://github.com/wevm/wagmi/blob/main/packages/core/src/actions/getBalance.ts#L69
but we're never reaching this catch block that is supposed to format using bytes32 instead of string

Error sample:

Viem seems to be throwing the right error though.
This is the error type we get if we listen to onError(error) of useBalance on wagmi side

useBalance.ts:48 ContractFunctionExecutionError: Position `3.496116881397033e+76` is out of bounds (`0 < position < 32`).

Contract Call:
  address:   0x9f8f72aa9304c8b593d555f12ef6589cc3a579a2
  function:  symbol()

Docs: https://viem.sh/docs/contract/readContract
Version: [email protected]
    at getContractError (getContractError.js:34:12)
    at readContract (readContract.js:67:98)
    at async Promise.all (:3001/index 2)
    at async readContracts (readContracts.js:50:17)
    at async getTokenBalance (getBalance.js:83:39)
    at async Object.queryFn (getBalance.js:16:29)Caused by: PositionOutOfBoundsError: Position `3.496116881397033e+76` is out of bounds (`0 < position < 32`).

Version: [email protected]
    at Object.assertPosition (cursor.js:23:19)
    at Object.setPosition (cursor.js:154:14)
    at decodeString (decodeAbiParameters.js:226:12)
    at decodeParameter (decodeAbiParameters.js:66:16)
    at decodeAbiParameters (decodeAbiParameters.js:41:35)
    at decodeFunctionResult (decodeFunctionResult.js:25:96)
    at readContract (readContract.js:59:104)
    at async Promise.all (:3001/index 2)
    at async readContracts (readContracts.js:50:17)
    at async getTokenBalance (getBalance.js:83:39)
    at async Object.queryFn (getBalance.js:16:29)

Link to Minimal Reproducible Example

No response

Steps To Reproduce

To replicate

Try to fetch MKR balance on Ethereum using useBalance
Viem will fail to read the symbol as string, should propagate an error that will be handled by wagmi, then retry formatting the symbol as bytes32, but code isn't reaching that catch block

link to contract symbol: https://etherscan.io/address/0x9f8f72aa9304c8b593d555f12ef6589cc3a579a2#readContract#F7
value failed to be parsed: 0x4d4b520000000000000000000000000000000000000000000000000000000000

What Wagmi package(s) are you using?

@wagmi/core

Versions

"@wagmi/core": "2.13.8",
"wagmi": "2.12.20",
"viem": "2.21.32",

[jxom]

Why is MKR returning bytes32 instead of a string? This means it does not follow the ERC20 spec: https://eips.ethereum.org/EIPS/eip-20#symbol

[odcey]

That's a good question, I have no idea.

But from what I've read from wagmi/viem codebase, it seems that this possibility was handled, am I right ?

But in this case, somehow, the error is not propagated enough to reach this: https://github.com/wevm/wagmi/blob/main/packages/core/src/actions/getBalance.ts#L69

[odcey]

By the way i'm fine closing this if you want, as MKR isn't respecting ERC20 standard, up to you if you want to fix, that might happen for other tokens though.

[github-actions]

This issue has been locked since it has been closed for more than 14 days.

If you found a concrete bug or regression related to it, please open a new bug report with a reproduction against the latest Wagmi version. If you have any questions or comments you can create a new discussion thread.