From aaa94a22223d3bee5e1684e8d5f543b8d05cdc3e Mon Sep 17 00:00:00 2001
From: weiihann <weihan774237@gmail.com>
Date: Fri, 17 Jan 2025 15:40:19 +0800
Subject: [PATCH] Bytes() return fixed array

---
 core/trie/bitarray.go      | 13 ++++++++-----
 core/trie/bitarray_test.go |  2 +-
 2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/core/trie/bitarray.go b/core/trie/bitarray.go
index b2bf95269..d1d28eab7 100644
--- a/core/trie/bitarray.go
+++ b/core/trie/bitarray.go
@@ -38,7 +38,8 @@ func NewBitArray(length uint8, val uint64) BitArray {
 // Returns the felt representation of the bit array.
 func (b *BitArray) Felt() felt.Felt {
 	var f felt.Felt
-	f.SetBytes(b.Bytes())
+	bt := b.Bytes()
+	f.SetBytes(bt[:])
 	return f
 }
 
@@ -47,7 +48,7 @@ func (b *BitArray) Len() uint8 {
 }
 
 // Returns the bytes representation of the bit array in big endian format
-func (b *BitArray) Bytes() []byte {
+func (b *BitArray) Bytes() [32]byte {
 	var res [32]byte
 
 	binary.BigEndian.PutUint64(res[0:8], b.words[3])
@@ -55,7 +56,7 @@ func (b *BitArray) Bytes() []byte {
 	binary.BigEndian.PutUint64(res[16:24], b.words[1])
 	binary.BigEndian.PutUint64(res[24:32], b.words[0])
 
-	return res[:]
+	return res
 }
 
 // Sets the bit array to the least significant 'n' bits of x.
@@ -512,15 +513,17 @@ func (b *BitArray) Copy() BitArray {
 // Returns the encoded string representation of the bit array.
 func (b *BitArray) EncodedString() string {
 	var res []byte
+	bt := b.Bytes()
 	res = append(res, b.len)
-	res = append(res, b.Bytes()...)
+	res = append(res, bt[:]...)
 	return string(res)
 }
 
 // Returns a string representation of the bit array.
 // This is typically used for logging or debugging.
 func (b *BitArray) String() string {
-	return fmt.Sprintf("(%d) %s", b.len, hex.EncodeToString(b.Bytes()))
+	bt := b.Bytes()
+	return fmt.Sprintf("(%d) %s", b.len, hex.EncodeToString(bt[:]))
 }
 
 func (b *BitArray) setFelt(f *felt.Felt) {
diff --git a/core/trie/bitarray_test.go b/core/trie/bitarray_test.go
index 123ed5244..4786eee2e 100644
--- a/core/trie/bitarray_test.go
+++ b/core/trie/bitarray_test.go
@@ -97,7 +97,7 @@ func TestBytes(t *testing.T) {
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			got := tt.ba.Bytes()
-			if !bytes.Equal(got, tt.want[:]) {
+			if !bytes.Equal(got[:], tt.want[:]) {
 				t.Errorf("BitArray.Bytes() = %v, want %v", got, tt.want)
 			}