improve: adding handling of odd-length hex strings in .

Signed-off-by: Nikolay Nedkov <[email protected]>

hex/hex.go

@@ -40,6 +40,12 @@ func DecodeString(str string) ([]byte, error) {
 func DecodeHex(str string) ([]byte, error) {
 	str = strings.TrimPrefix(str, "0x")
 
+	// Check if the string has an odd length
+	if len(str)%2 != 0 {
+		// Prepend a '0' to make it even-length
+		str = "0" + str
+	}
+
 	return hex.DecodeString(str)
 }
 

hex/hex_test.go

@@ -1,11 +1,13 @@
 package hex
 
 import (
+	"encoding/hex"
 	"math"
 	"math/big"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 func TestEncodeDecodeBig(t *testing.T) {
@@ -14,3 +16,37 @@ func TestEncodeDecodeBig(t *testing.T) {
 	d := DecodeBig(e)
 	assert.Equal(t, b.Uint64(), d.Uint64())
 }
+
+// Define a struct for test cases
+type TestCase struct {
+	input  string
+	output []byte
+	err    error
+}
+
+// Unit test function
+func TestDecodeHex(t *testing.T) {
+	testCases := []TestCase{
+		{"0", []byte{0}, nil},
+		{"00", []byte{0}, nil},
+		{"0x0", []byte{0}, nil},
+		{"0x00", []byte{0}, nil},
+		{"1", []byte{1}, nil},
+		{"01", []byte{1}, nil},
+		{"", []byte{}, hex.ErrLength},
+		{"0x", []byte{}, hex.ErrLength},
+		{"zz", []byte{}, hex.InvalidByteError('z')},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.input, func(t *testing.T) {
+			output, err := DecodeHex(tc.input)
+			if tc.err != nil {
+				require.Error(t, tc.err, err)
+			} else {
+				require.NoError(t, err)
+			}
+			require.Equal(t, output, tc.output)
+		})
+	}
+}