From 332a3c7984229a7e3a9a8a277f92942299616fdb Mon Sep 17 00:00:00 2001
From: Greg Thornton <xdissent@me.com>
Date: Sun, 23 Jun 2013 14:04:59 -0500
Subject: [PATCH] feat(Angular.js): skip JSON.stringify for undefined

Return early in `angular.toJson` if the object to be stringified is `undefined`.
IE8 stringifies `undefined` to `'undefined'` whereas other browsers return
`undefined`. This normalizes behavior and passes currently broken unit tests
in IE8.
---
 src/Angular.js      | 3 ++-
 test/AngularSpec.js | 4 ++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/Angular.js b/src/Angular.js
index ec3be068c17f..01b37969feaa 100644
--- a/src/Angular.js
+++ b/src/Angular.js
@@ -751,9 +751,10 @@ function toJsonReplacer(key, value) {
  *
  * @param {Object|Array|Date|string|number} obj Input to be serialized into JSON.
  * @param {boolean=} pretty If set to true, the JSON output will contain newlines and whitespace.
- * @returns {string} Jsonified string representing `obj`.
+ * @returns {string|undefined} Jsonified string representing `obj`.
  */
 function toJson(obj, pretty) {
+  if (typeof obj === 'undefined') return undefined;
   return JSON.stringify(obj, toJsonReplacer, pretty ? '  ' : null);
 }
 
diff --git a/test/AngularSpec.js b/test/AngularSpec.js
index febc02269035..8e4fbb1a7d32 100644
--- a/test/AngularSpec.js
+++ b/test/AngularSpec.js
@@ -879,5 +879,9 @@ describe('angular', function() {
     it('should not serialize scope instances', inject(function($rootScope) {
       expect(toJson({key: $rootScope})).toEqual('{"key":"$SCOPE"}');
     }));
+
+    it('should serialize undefined as undefined', function() {
+      expect(toJson(undefined)).toEqual(undefined);
+    });
   });
 });