From 8f845961427162f6fd4084913bb8e9258e6255ab Mon Sep 17 00:00:00 2001
From: Berkeley Martinez <Berkeley@robotie.com>
Date: Mon, 5 Oct 2015 16:38:58 -0700
Subject: [PATCH] Fix 500 out of range bug when completing last challenge

---
 server/boot/challenge.js | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/server/boot/challenge.js b/server/boot/challenge.js
index 15cb507855..adf4c95c21 100644
--- a/server/boot/challenge.js
+++ b/server/boot/challenge.js
@@ -183,9 +183,9 @@ module.exports = function(app) {
                 'could not find challenge block for ' + challenge.block
               );
             }
-            const nextBlock$ = blocks$.elementAt(blockIndex + 1);
-            const firstChallengeOfNextBlock$ = nextBlock$
-              .map(block => block.challenges[0]);
+            const firstChallengeOfNextBlock$ = blocks$
+              .elementAtOrDefault(blockIndex + 1, {})
+              .map(({ challenges = [] }) => challenges[0]);
 
             return blocks$
               .elementAt(blockIndex)
@@ -214,6 +214,9 @@ module.exports = function(app) {
           });
       })
       .map(nextChallenge => {
+        if (!nextChallenge) {
+          return null;
+        }
         nextChallengeName = nextChallenge.dashedName;
         return nextChallengeName;
       })