Introduce SequentialOperations abstraction for signature-based ops

[k06a]

Beware that this PR is build on top of #3848 and includes its commits

PR Checklist

TBD

• Tests
• Documentation
• Changelog entry

[k06a]

Abstraction related to this implementation is also discussed here: ethereum/EIPs#6077

[Amxx]

Hello @k06a

This looks like a very significant change. You are rightfully targeting next-5.0 as this would be breaking. Still, I believe we should have more discussion before jumping to an implementation.

I appreciate that there is standardization effort making an ERC with that, but it is still in a very early stage, and likely to evolve. Maybe a good option would be to keep the current interface/approach, and "just" change the storage under the hood to be future proof and allow this to be implemented as a non-storage-breaking change during 5.x lifecycle.

There are other nonce related changes that we could implement. I'm thinking of the timeline system described here.

Lets discuss features first. Don't worry, the 5.0 train is not leaving anytime soon :)

[Amxx]

Note: we might reopen this based on the discussion in #3927

[TrejGun]

@k06a please explain where operationHash comes from?

[k06a]

@TrejGun it depends on specific operation EIP/definition.

[TrejGun]

@k06a can you show any example?

[k06a]

@TrejGun my bad, you should use EIP-712 for structured data hash.

[TrejGun]

@k06a
Ok I will ask again)

did you abstract this code as operationHash?

       keccak256(
          abi.encode(
            SOME_TYPEHASH,
            same_variable1,
            same_variable2,
            ...
          )
        )

I ask this because I really like this abstraction and it does not look like you are doing this in solidity so maybe in JS and I want to understand how. For now I use ethers._signTypedData that will return _hashTypedDataV4(operationHash) but not just operationHash. So how can I generate it?

looks like ethers.utils.AbiCoder.encode(["uint256"], [1]); but it also looks like a big pain for complex types

[k06a]

@TrejGun maybe this would work for you: https://github.com/ethers-io/ethers.js/blob/ce8f1e4015c0f27bf178238770b1325136e3351a/packages/hash/src.ts/typed-data.ts#L371

[TrejGun]

@k06a thanks