chore: move Subject creation into helper function

cmd/check/root.go

@@ -49,19 +49,9 @@ func newCheckCmd() *cobra.Command {
 			namespace := args[2]
 			object := args[3]
 
-			var s *rts.Subject
-
-			// distinguish between subjectSet and subjectID
-			if strings.Contains(subject, ":") {
-				su := &ketoapi.SubjectSet{}
-				su, err := su.FromString(subject)
-				if err != nil {
-					return err
-				}
-
-				s = rts.NewSubjectSet(su.Namespace, su.Object, su.Relation)
-			} else {
-				s = rts.NewSubjectID(subject)
+			s, err := genSubject(subject)
+			if err != nil {
+				return err
 			}
 
 			cl := rts.NewCheckServiceClient(conn)
@@ -91,6 +81,25 @@ func newCheckCmd() *cobra.Command {
 	return cmd
 }
 
+// generate from given string a SubjectID or a SubjectSet embedded into a Subject
+func genSubject(subject string) (*rts.Subject, error) {
+	var s *rts.Subject
+
+	// distinguish between subjectSet and subjectID
+	if strings.Contains(subject, ":") {
+		su := &ketoapi.SubjectSet{}
+		su, err := su.FromString(subject)
+		if err != nil {
+			return nil, err
+		}
+
+		s = rts.NewSubjectSet(su.Namespace, su.Object, su.Relation)
+	} else {
+		s = rts.NewSubjectID(subject)
+	}
+	return s, nil
+}
+
 func RegisterCommandsRecursive(parent *cobra.Command) {
 	parent.AddCommand(newCheckCmd())
 }