refactor: simplify io code and make utils module independent

internal/serialization/validation.go

@@ -0,0 +1,25 @@
+package serialization
+
+import (
+	"github.com/go-playground/validator/v10"
+	"github.com/yusing/go-proxy/internal/gperr"
+)
+
+var validate = validator.New()
+
+var ErrValidationError = gperr.New("validation error")
+
+type CustomValidator interface {
+	Validate() gperr.Error
+}
+
+func Validator() *validator.Validate {
+	return validate
+}
+
+func MustRegisterValidation(tag string, fn validator.Func) {
+	err := validate.RegisterValidation(tag, fn)
+	if err != nil {
+		panic(err)
+	}
+}