From 369c1a2769c4709e48b92f703a2b4adad974efbd Mon Sep 17 00:00:00 2001
From: Alex Van Camp <email@alexvan.camp>
Date: Tue, 17 Feb 2015 11:17:02 -0600
Subject: [PATCH] log a better error message when failing to mount an extension
 as an express app

---
 lib/server/extensions.js |  2 +-
 lib/server/index.js      | 12 ++++++++++--
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/lib/server/extensions.js b/lib/server/extensions.js
index 3d0d35f07..c27b9d05a 100644
--- a/lib/server/extensions.js
+++ b/lib/server/extensions.js
@@ -77,7 +77,7 @@ function _loadExtension(bundle) {
         try {
             var extension = require(extPath)(new ExtensionApi(bundle));
             if (bundle.extension.express) {
-                expressExtensions.push(extension);
+                expressExtensions.push([extension, bundle.name]);
                 log.info('Mounted %s extension as an express app', bundle.name);
             } else {
                 log.info('Mounted %s extension as a generic extension', bundle.name);
diff --git a/lib/server/index.js b/lib/server/index.js
index a1bf158bb..5e9f08952 100644
--- a/lib/server/index.js
+++ b/lib/server/index.js
@@ -54,8 +54,16 @@ exports.start = function() {
 
     extensionManager = require('./extensions.js');
     extensionManager.on('extensionsLoaded', function() {
-        extensionManager.getExpressExtensions().forEach(function(extension) {
-            app.use(extension);
+        extensionManager.getExpressExtensions().forEach(function(extData) {
+            var extension = extData[0];
+            var name = extData[1];
+            try {
+                app.use(extension);
+            } catch(e) {
+                log.error('Failed to mount extension for bundle "%s" as an express app.'
+                    + '\n\tEither make sure your extension is actually exporting an express app,'
+                    + '\n\tor set "extension.express" to "false" in your nodecg.json', name);
+            }
         });
 
         exports.emit('extensionsLoaded');