From 2ea77a940902146d91c854440f49ca847a6cde3f Mon Sep 17 00:00:00 2001
From: Avital Oliver <avital@thewe.net>
Date: Fri, 20 Jun 2014 12:17:58 -0700
Subject: [PATCH] Even better checks for the arguments to UI.insert

---
 packages/ui/render.js       | 4 +++-
 packages/ui/render_tests.js | 5 ++++-
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/packages/ui/render.js b/packages/ui/render.js
index 0259f1b459..3867219d93 100644
--- a/packages/ui/render.js
+++ b/packages/ui/render.js
@@ -173,8 +173,10 @@ UI.insert = function (renderedTemplate, parentElement, nextNode) {
   // parentElement must be a DOM node. in particular, can't be the
   // result of a call to `$`. Can't check if `parentElement instanceof
   // Node` since 'Node' is undefined in IE8.
-  if (typeof parentElement.nodeType !== 'number')
+  if (! parentElement || typeof parentElement.nodeType !== 'number')
     throw new Error("'parentElement' must be a DOM node");
+  if (nextNode && typeof nextNode.nodeType !== 'number') // 'nextNode' is optional
+    throw new Error("'nextNode' must be a DOM node");
 
   if (! renderedTemplate.dom)
     throw new Error("Expected template rendered with UI.render");
diff --git a/packages/ui/render_tests.js b/packages/ui/render_tests.js
index e3ba814fcd..915eff7600 100644
--- a/packages/ui/render_tests.js
+++ b/packages/ui/render_tests.js
@@ -626,7 +626,10 @@ Tinytest.add("ui - UI.insert fails on jQuery objects", function (test) {
   });
   test.throws(function () {
     UI.insert(UI.render(tmpl), $('body'));
-  }, /must be a DOM node/);
+  }, /'parentElement' must be a DOM node/);
+  test.throws(function () {
+    UI.insert(UI.render(tmpl), document.body, $('body'));
+  }, /'nextNode' must be a DOM node/);
 });
 
 Tinytest.add("ui - UI.getDataContext", function (test) {