feat: safe websocket server implementation

internal/nil_checker.go

@@ -0,0 +1,40 @@
+package internal
+
+import (
+	"fmt"
+	"reflect"
+	"strings"
+)
+
+func NilChecker(data any) error {
+	val := reflect.ValueOf(data)
+
+	if val.Kind() == reflect.Ptr {
+		val = val.Elem()
+	}
+
+	valType := val.Type()
+
+	if val.Kind() != reflect.Struct {
+		return fmt.Errorf("data is not a struct")
+	}
+
+	nilFields := []string{}
+	for i := range val.NumField() {
+		field := val.Field(i)
+		fieldType := valType.Field(i)
+		tagValue := fieldType.Tag.Get("nil_checker")
+
+		if tagValue == "required" {
+			if field.Kind() == reflect.Ptr {
+				if field.IsNil() {
+					nilFields = append(nilFields, fieldType.Name)
+				}
+			}
+		}
+	}
+	if len(nilFields) > 0 {
+		return fmt.Errorf("%s is empty", strings.Join(nilFields, ","))
+	}
+	return nil
+}