Added unit tests for IsHexValid function

types/types.go

@@ -88,7 +88,7 @@ type ArgHash common.Hash
 
 // UnmarshalText unmarshals from text
 func (arg *ArgHash) UnmarshalText(input []byte) error {
-	if !HexIsValid(string(input)) {
+	if !IsHexValid(string(input)) {
 		return fmt.Errorf("invalid hash, it needs to be a hexadecimal value")
 	}
 
@@ -123,8 +123,8 @@ func decodeToHex(b []byte) ([]byte, error) {
 	return hex.DecodeString(str)
 }
 
-// HexIsValid checks if the provided string is a valid hexadecimal value
-func HexIsValid(s string) bool {
+// IsHexValid checks if the provided string is a valid hexadecimal value
+func IsHexValid(s string) bool {
 	str := strings.TrimPrefix(s, "0x")
 	for _, b := range []byte(str) {
 		if !(b >= '0' && b <= '9' || b >= 'a' && b <= 'f' || b >= 'A' && b <= 'F') {

types/types_test.go

@@ -0,0 +1,41 @@
+package types
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestIsHexValid(t *testing.T) {
+	tests := []struct {
+		name string
+		s    string
+		want bool
+	}{
+		{
+			name: "valid hex without 0x prefix",
+			s:    "76616c69642068657820776974686f757420307820707265666978",
+			want: true,
+		},
+		{
+			name: "valid hex with 0x prefix",
+			s:    "0x76616c696420686578207769746820307820707265666978",
+			want: true,
+		},
+		{
+			name: "invalid hex without 0x prefix",
+			s:    "76616c696invalid07769746820307820707265666978",
+			want: false,
+		},
+		{
+			name: "invalid hex with 0x prefix",
+			s:    "0x76616c696invalid07769746820307820707265666978",
+			want: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			require.Equal(t, tt.want, IsHexValid(tt.s))
+		})
+	}
+}