Add back hex ut to keep consistent with dev

hex/hex_test.go

@@ -0,0 +1,52 @@
+package hex
+
+import (
+	"encoding/hex"
+	"math"
+	"math/big"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestEncodeDecodeBig(t *testing.T) {
+	b := big.NewInt(math.MaxInt64)
+	e := EncodeBig(b)
+	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)
+		})
+	}
+}