How to call eth_signTypedData_v4 in integration test?

[stefan-girlich]

I am trying to invoke different wagmi functions (e.g. signTypedData) in a Jest-driven test suite for integration testing. I want to sign some data and finally invoke a smart contract on Rinkeby.

My test setup is largely derived from wagmi's codebase and just hardcodes Rinkeby as the chain to use. My test code calls signTypedData and is supposed to invoke other wagmi functions in the future, including sending transactions.

As of now, both RPC providers (Alchemy and Infura) will tell me that the method eth_signTypedData_v4 is not available. Example response from Infura:

  reason: 'processing response error',
  code: 'SERVER_ERROR',
  body: '{"jsonrpc":"2.0","id":42,"error":{"code":-32601,"message":"The method eth_signTypedData_v4 does not exist/is not available"}}',
  requestMethod: 'POST',
  url: 'https://rinkeby.infura.io/v3/<MY_PROJECT_ID>'

1. Would you know why both providers do not provide the signing function via their APIs?
2. My test wallet exists on Rinkeby and I instantiate it via const wallet = new Wallet({privateKey, address}); return provider.getSigner(wallet.address) (see linked code). Since Metamask uses Infura by default, I assume that I am simply unauthorized to call eth_signTypedData_v4 via API. How would I provide the right auth information in this case?

Thanks so much for your help!

[stefan-girlich]

Root cause

The test setup I adapted from the wagmi codebase calls provider.getSigner(wallet.address) to create a JsonRpcSigner which will try to invoked eth_signTypedData_v4 via Infura/Alchemy, both of which don't provide this method in their respective APIs:

export function getSigners() {
    const provider = getProvider()
    const signers = accounts.map(x => {
        const wallet = new Wallet({
            privateKey: x.privateKey,
            address: x.address,
        })
        return provider.getSigner(wallet.address)
    })
    return signers
}

Workaround

export function getSigners() {
    const signers = accounts.map(x => {
        return new Wallet({
            privateKey: x.privateKey,
            address: x.address,
        })
    })
    return signers
}

Possible aftereffect

I expect on-chain operations (e.g. sending transactions) to fail since the wallet does not feature a provider.
=> Which approach should be used to enable both local signing and on-chain operations?

[Na3aga]

@stefan-girlich did you manage to write automated tests with local signing ?

[0xPro]

i'd like to know as well please