fixed mock s3 list dirs

internal/s3/mock.go

@@ -47,14 +47,30 @@ func (m *mockS3) ListBuckets(ctx context.Context) ([]string, error) {
 func (m *mockS3) ListObjects(ctx context.Context, id types.ID) ([]Object, error) {
 	var results []Object
 
+	dirs := make(map[string]bool)
+
+	depth := len(strings.Split(id.Key, "/"))
+
 	for k, v := range m.objects {
 		if k.Bucket == id.Bucket {
 			if k.Parent().Key == id.Key {
 				results = append(results, *mockObjToObject(v, k))
+			} else if strings.HasPrefix(k.Key, id.Key) {
+				s := strings.Join(strings.Split(k.Key, "/")[:depth], "/") + "/"
+				dirs[s] = true
 			}
 		}
 	}
 
+	for k := range dirs {
+		results = append(results, Object{
+			ID: types.ID{
+				Bucket: id.Bucket,
+				Key:    k,
+			},
+		})
+	}
+
 	return results, nil
 }