[Bug] bincode deserialization fails for fixed-size byte arrays

[Wollac]

Component

primitives

What version of Alloy are you on?

alloy-primitives v0.3.1

Operating System

None

Describe the bug

Trying to use bincode to deserialize FixedBytes<N> fails because deserializer.deserialize_any is not supported.

Code snippet to reproduce this bug:

let hash = B256::ZERO;
bincode::deserialize::<B256>(&bincode::serialize(&hash).unwrap()).unwrap();

The serde documentation also discourages the use of deserialize_any for this very reason:

When implementing Deserialize, you should avoid relying on Deserializer::deserialize_any unless you need to be told by the Deserializer what type is in the input. Know that relying on Deserializer::deserialize_any means your data type will be able to deserialize from self-describing formats only, ruling out Postcard and many others.

However, as I understand #202, JSON deserialization support for either a byte array, byte sequence, or string was explicitly required. Here I see a possible compromise to also check is_human_readable() in the deserialization and keep the current parsing only for human readable, e.g. JSON, and use deserializer.deserialize_bytes otherwise, which would also allow bincode and similar formats.

If this approach is acceptable, I would be happy to provide a PR.

[prestwich]

approach sounds good to me, thanks ✔️