Solidity Hashing Algorithms array support

[Gudahtt]

The Solidity hashing algorithms (solidityPack, solidityKeccak256, and soliditySha256) do not support array types in v5. Yet Solidity's abi.encodePacked() does support array types. It was my understanding that these methods were meant to imitate abi.encodePacked(), so they should support array types as well.

[Gudahtt]

This is my last blocker for migrating from ethereumjs-abi to ethers. I wrote an adapter to accommodate all of the other functional differences between the two packages, but this difference was difficult to handle. Essentially I'd need to re-implement the entire function.

[ricmoo]

They should support arrays.

Can you give an example of the code you are using? Keep in mind the Solidity packing algorithms do not support packing any type that requires the v2 coder in Solidity, unless the have changed that restriction.

[Gudahtt]

Oh sorry, I thought this was a known missing feature. There was a related TODO comment here: https://github.com/ethers-io/ethers.js/blob/master/packages/solidity/src.ts/index.ts#L73

I also noticed there is an isArray parameter for the internal _pack function that is never set: https://github.com/ethers-io/ethers.js/blob/master/packages/solidity/src.ts/index.ts#L15

I can comment later with a minimal example.

[ricmoo]

Enums ended up being unsupportable in general, although there was a discussion discussing clamping their size to a uint8.

Yeah, an example which works in solidity but not in ethers would be great. Thanks! :)

[Gudahtt]

🤦 My bad, I had a mistake in my code. It does support arrays, as you suggested. I had thought it was ethers after digging in and seeing that comment and the unused isArray parameter. Sorry about that! Thanks for the prompt reply.

[ricmoo]

No worries. :)

The isArray parameter is used to handle the strange way non-standard packing handles packing arrays, but it’s used. :)

[ricmoo]

(Or maybe it’s used to handle an experimental packing I thought they might use; I don’t really recall. In v6 I will look into it again. :))