Dynamic bitfield length for lighthouse issue #6757 (#46)

* add dynamic bitvector module

* add dynamic module

* make dynamic submodule to preserve private fields

* comment

* add tests, clean up files

* comment cleanup

* tests proving from_bytes equivalence and max_length usage

* clippy

* fix potential out of bounds and remove unwraps in union and intersection

* add serde test

* clippy (not mine)

* fix failing test

* test serialize and deserialise

* serde testing

* deserialize serde test

* remove test unwraps

* tidy error message in tests

* Use iter_mut().enumerate() in bitvector_dynamic

* cargo fmt

Author: jking-aus

ssz/Cargo.toml

@@ -16,6 +16,7 @@ name = "ssz"
 [dev-dependencies]
 alloy-primitives = { version = "1.0", features = ["getrandom"] }
 ethereum_ssz_derive = { version = "0.9.0", path = "../ssz_derive" }
+serde_json = "1.0.0"
 
 [dependencies]
 alloy-primitives = "1.0"

ssz/src/bitfield.rs

@@ -5,6 +5,7 @@ use serde::ser::{Serialize, Serializer};
 use serde_utils::hex::{encode as hex_encode, PrefixedHexVisitor};
 use smallvec::{smallvec, SmallVec, ToSmallVec};
 use typenum::Unsigned;
+pub mod bitvector_dynamic;
 
 /// Returned when an item encounters an error.
 #[derive(PartialEq, Debug, Clone)]
@@ -406,7 +407,7 @@ impl<T: BitfieldBehaviour> Bitfield<T> {
                 .get(i / 8)
                 .ok_or(Error::OutOfBounds { i, len: self.len })?;
 
-            Ok(*byte & 1 << (i % 8) > 0)
+            Ok(*byte & (1 << (i % 8)) > 0)
         } else {
             Err(Error::OutOfBounds { i, len: self.len })
         }