refactor!: adapt merkle path to use repeated bytes in favour of strin…

…gs (#6633)

* refactor: adapt merkle path to use repeated bytes in favour of strings

* chore: add changelog

CHANGELOG.md

@@ -58,6 +58,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * (apps/27-interchain-accounts) [\#6433](https://github.com/cosmos/ibc-go/pull/6433) Use UNORDERED as the default ordering for new ICA channels.
 * (apps/transfer) [\#6440](https://github.com/cosmos/ibc-go/pull/6440) Remove `GetPrefixedDenom`.
 * (apps/transfer) [\#6508](https://github.com/cosmos/ibc-go/pull/6508) Remove the `DenomTrace` type.
+* (23-commmitment) [\#6633](https://github.com/cosmos/ibc-go/pull/6633) MerklePath has been changed to use `repeated bytes` in favour of `repeated strings`.
 
 ### State Machine Breaking
 

modules/core/23-commitment/types/merkle.go

@@ -71,8 +71,13 @@ var _ exported.Path = (*MerklePath)(nil)
 // NewMerklePath creates a new MerklePath instance
 // The keys must be passed in from root-to-leaf order
 func NewMerklePath(keyPath ...string) MerklePath {
+	var path [][]byte
+	for _, key := range keyPath {
+		path = append(path, []byte(key))
+	}
+
 	return MerklePath{
-		KeyPath: keyPath,
+		KeyPath: path,
 	}
 }
 
@@ -81,7 +86,7 @@ func (mp MerklePath) GetKey(i uint64) ([]byte, error) {
 	if i >= uint64(len(mp.KeyPath)) {
 		return nil, fmt.Errorf("index out of range. %d (index) >= %d (len)", i, len(mp.KeyPath))
 	}
-	return []byte(mp.KeyPath[i]), nil
+	return mp.KeyPath[i], nil
 }
 
 // Empty returns true if the path is empty
@@ -95,7 +100,10 @@ func ApplyPrefix(prefix exported.Prefix, path MerklePath) (MerklePath, error) {
 	if prefix == nil || prefix.Empty() {
 		return MerklePath{}, errorsmod.Wrap(ErrInvalidPrefix, "prefix can't be empty")
 	}
-	return NewMerklePath(append([]string{string(prefix.Bytes())}, path.KeyPath...)...), nil
+
+	return MerklePath{
+		KeyPath: append([][]byte{prefix.Bytes()}, path.KeyPath...),
+	}, nil
 }
 
 // VerifyMembership verifies the membership of a merkle proof against the given root, path, and value.

modules/core/23-commitment/types/merkle_test.go

@@ -145,7 +145,7 @@ func TestApplyPrefix(t *testing.T) {
 
 	pathStr := "pathone/pathtwo/paththree/key"
 	path := types.MerklePath{
-		KeyPath: []string{pathStr},
+		KeyPath: [][]byte{[]byte(pathStr)},
 	}
 
 	prefixedPath, err := types.ApplyPrefix(prefix, path)

proto/ibc/core/commitment/v1/commitment.proto

@@ -26,7 +26,7 @@ message MerklePrefix {
 // arbitrary structured object (defined by a commitment type).
 // MerklePath is represented from root-to-leaf
 message MerklePath {
-  repeated string key_path = 1;
+  repeated bytes key_path = 1;
 }
 
 // MerkleProof is a wrapper type over a chain of CommitmentProofs.