Hardhat Support for eth_signTransaction

[jiaochangyang]

Hardhat node does not currently have support for eth_signTransaction, which is defined in the Ethereum JSON-RPC specifications. It would be good to have this particular feature for dApp development purposes as it would allow for simpler unit-testing through unlocked accounts, while still handling raw transaction submission the same way.

[github-actions[bot]]

This issue is also being tracked on Linear.

We use Linear to manage our development process, but we keep the conversations on Github.

LINEAR-ID: 9a131121-a6a9-4b7f-a2d6-dee349232fdc

[sisco0]

Should the required functionality not be similar to the current implementation of eth_sendTransactionAction in packages/hardhat-core/src/internal/hardhat-network/provider/modules/eth.ts? Just replacing the this._sendTransactionAndReturnHash(tx) source code line of sendTransaction at the end of the function by tx as shown in the screenshot below.

[jiaochangyang]

I believe you are right that this functionality does what is requested. Would it be possible to expose this as a public functionality?

[jiaochangyang]

Any chance of this getting picked up?

[fvictorio]

I'm not (in principle) against implementing this; we've just had other priorities. Also, no one else seems to be asking for this to be implemented (it's not a very commonly used method AFAIK; you normally send the transaction and your library, wallet or node handles it).

Maybe having specific use cases that are not possible right now would help us prioritize this.

[jeanregisser]

Ah I was just bitten by this trying to use signTransaction from a client provided by hardhat-viem and was getting unknown account. A bit surprising when sendTransaction and signMessage were working fine.

My use case was signing an approval + swap manually, with precise control of the nonce. But I guess I can just use sendTransaction for now.