Handle missing/empty `shortener.url`

main.go

@@ -6,6 +6,7 @@ import (
 	"github.com/prometheus/client_golang/prometheus/promauto"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"go.mongodb.org/mongo-driver/bson"
+	"go.mongodb.org/mongo-driver/bson/primitive"
 	"go.mongodb.org/mongo-driver/mongo"
 	"go.mongodb.org/mongo-driver/mongo/options"
 	"go.mongodb.org/mongo-driver/x/mongo/driver/connstring"
@@ -17,13 +18,12 @@ import (
 	"time"
 )
 
-type shortenerAttrType struct {
-	Slug string
-	URL  string
-}
-
 type inventoryItemType struct {
-	Shortener shortenerAttrType
+	ID primitive.ObjectID `bson:"_id" json:"_id,omitempty"`
+	Shortener struct {
+		Slug string `bson:"slug" json:"slug"`
+		URL  string `bson:"url" json:"url"`
+	} `bson:"shortener" json:"shortener"`
 }
 
 var reValid = regexp.MustCompile("^[a-zA-Z0-9]{4,6}$")
@@ -58,6 +58,9 @@ func wrapper(coll *mongo.Collection) func(w http.ResponseWriter, r *http.Request
 
 		counterFound.Inc()
 		var u = doc.Shortener.URL
+		if u == "" {
+			u = strings.Replace(redirectFound, "%s", doc.ID.Hex(), 1)
+		}
 		http.Redirect(w, r, u, 302)
 		log.Printf("Redirecting %s to %s\n", slug, doc.Shortener.URL)
 	}