refactor mw example

pkg/use-case-helper/tycovar.go

@@ -0,0 +1,8 @@
+package usecasehelper
+
+type MWType string
+
+const (
+	MWTPre  MWType = "Pre"
+	MWTPost MWType = "Post"
+)

pkg/use-case-helper/use-case-helper.go

@@ -3,6 +3,7 @@ package usecasehelper
 import (
 	"errors"
 	"fmt"
+	"strings"
 
 	pl "simrs-vx/pkg/logger"
 
@@ -46,3 +47,10 @@ func HandleReadError(err error, event *pl.Event, itemType string, id interface{}
 
 	return pl.SetLogError(*event, nil)
 }
+
+func GetMiddlewareErrorCode(mwType MWType) string {
+	if strings.Contains(string(mwType), "Pre") {
+		return "MW_PRE_FAILED"
+	}
+	return "MW_POST_FAILED"
+}