From 23b077529edf5d9beaac05db96e9fee3132501e1 Mon Sep 17 00:00:00 2001
From: Jun Kimura <jun.kimura@datachain.jp>
Date: Wed, 7 Feb 2024 10:20:21 +0900
Subject: [PATCH] fix serialization for sync committee bits

Signed-off-by: Jun Kimura <jun.kimura@datachain.jp>
---
 crates/ibc/src/errors.rs | 14 ++++++--------
 crates/ibc/src/types.rs  | 16 ++++++++++------
 2 files changed, 16 insertions(+), 14 deletions(-)

diff --git a/crates/ibc/src/errors.rs b/crates/ibc/src/errors.rs
index d9eee09..1297540 100644
--- a/crates/ibc/src/errors.rs
+++ b/crates/ibc/src/errors.rs
@@ -76,8 +76,6 @@ pub enum Error {
     EthereumConsensusError(ethereum_consensus::errors::Error),
     /// decode error: `{0}`
     Decode(prost::DecodeError),
-    /// ssz deserialize error: `{0}`
-    SSZDeserialize(ssz_rs::DeserializeError),
     /// ics02 error: `{0}`
     ICS02(ClientError),
     /// ics24 error: `{0}`
@@ -88,6 +86,12 @@ pub enum Error {
     TimestampOverflowError(TimestampOverflowError),
     /// parse timestamp error: `{0}`
     ParseTimestampError(ParseTimestampError),
+    /// deserialize sync committee bits error: `{parent}` sync_committee_size={sync_committee_size} sync_committee_bits={sync_committee_bits:?}
+    DeserializeSyncCommitteeBitsError {
+        parent: ssz_rs::DeserializeError,
+        sync_committee_size: usize,
+        sync_committee_bits: Vec<u8>,
+    },
 }
 
 impl From<Error> for ClientError {
@@ -134,12 +138,6 @@ impl From<ValidationError> for Error {
     }
 }
 
-impl From<ssz_rs::DeserializeError> for Error {
-    fn from(value: ssz_rs::DeserializeError) -> Self {
-        Self::SSZDeserialize(value)
-    }
-}
-
 impl From<ContextError> for Error {
     fn from(value: ContextError) -> Self {
         Self::ContextError(value)
diff --git a/crates/ibc/src/types.rs b/crates/ibc/src/types.rs
index 6825949..8fa9433 100644
--- a/crates/ibc/src/types.rs
+++ b/crates/ibc/src/types.rs
@@ -178,15 +178,14 @@ pub(crate) fn convert_execution_update_to_proto(
     }
 }
 
+/// CONTRACT: `SYNC_COMMITTEE_SIZE` must be greater than 0
 pub(crate) fn convert_sync_aggregate_to_proto<const SYNC_COMMITTEE_SIZE: usize>(
     sync_aggregate: SyncAggregate<SYNC_COMMITTEE_SIZE>,
 ) -> ProtoSyncAggregate {
+    let sync_committee_bits = ssz_rs::serialize(&sync_aggregate.sync_committee_bits)
+        .expect("failed to serialize sync_committee_bits: this should never happen unless `SYNC_COMMITTEE_SIZE` is 0");
     ProtoSyncAggregate {
-        sync_committee_bits: sync_aggregate
-            .sync_committee_bits
-            .iter()
-            .map(|b| if b == true { 1 } else { 0 })
-            .collect(),
+        sync_committee_bits,
         sync_committee_signature: sync_aggregate.sync_committee_signature.0.to_vec(),
     }
 }
@@ -197,7 +196,12 @@ pub(crate) fn convert_proto_sync_aggregate<const SYNC_COMMITTEE_SIZE: usize>(
     Ok(SyncAggregate {
         sync_committee_bits: Bitvector::<SYNC_COMMITTEE_SIZE>::deserialize(
             sync_aggregate.sync_committee_bits.as_slice(),
-        )?,
+        )
+        .map_err(|e| Error::DeserializeSyncCommitteeBitsError {
+            parent: e,
+            sync_committee_size: SYNC_COMMITTEE_SIZE,
+            sync_committee_bits: sync_aggregate.sync_committee_bits,
+        })?,
         sync_committee_signature: Signature::try_from(sync_aggregate.sync_committee_signature)?,
     })
 }