fix

internal/validator/product_outlet_price_validator.go

@@ -2,6 +2,7 @@ package validator
 
 import (
 	"errors"
+	"fmt"
 
 	"apskel-pos-be/internal/constants"
 	"apskel-pos-be/internal/contract"
@@ -71,8 +72,7 @@ func (v *ProductOutletPriceValidatorImpl) ValidateBulkCreateRequest(req *contrac
 			return errors.New("outlet_id is required for each price entry"), constants.MissingFieldErrorCode
 		}
 		if p.Price < 0 {
-			_ = i
-			return errors.New("price must be non-negative for each price entry"), constants.MalformedFieldErrorCode
+			return fmt.Errorf("price at index %d must be non-negative", i), constants.MalformedFieldErrorCode
 		}
 	}