From c42081354514ebefd04bbedd6079a88cd0485825 Mon Sep 17 00:00:00 2001
From: Brent Vatne <brentvatne@gmail.com>
Date: Fri, 8 Jun 2018 17:44:32 -0700
Subject: [PATCH] Fix ScenesReducer test

---
 packages/react-navigation/src/views/ScenesReducer.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/react-navigation/src/views/ScenesReducer.js b/packages/react-navigation/src/views/ScenesReducer.js
index 2ef07a06..0c2ae5e7 100644
--- a/packages/react-navigation/src/views/ScenesReducer.js
+++ b/packages/react-navigation/src/views/ScenesReducer.js
@@ -70,7 +70,7 @@ export default function ScenesReducer(
   // It will be resolved in a better way when we re-write Transitioner
   scenes.forEach(scene => {
     const { route } = scene;
-    if (descriptors[route.key]) {
+    if (descriptors && descriptors[route.key]) {
       scene.descriptor = descriptors[route.key];
     }
   });