From 2120b27b22efd58622c4d2919ee5a9241bc233d3 Mon Sep 17 00:00:00 2001
From: Jason Davies <jason@jasondavies.com>
Date: Fri, 3 Dec 2010 13:01:58 +0000
Subject: [PATCH] Fix _.isEquals() for wrapped objects

This caught me out when writing some unit tests that use _.isEquals().
They were all passing even though I knew they shouldn't be, and I
realised I was checking equality with a wrapped object that I'd
forgotten to unwrap.
---
 test/objects.js | 8 +++++---
 underscore.js   | 3 +++
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/test/objects.js b/test/objects.js
index b47de7fc4..f0a60ecfe 100644
--- a/test/objects.js
+++ b/test/objects.js
@@ -45,13 +45,15 @@ $(document).ready(function() {
     ok(_.isEqual(moe, clone), 'deep equality is true');
     ok(_(moe).isEqual(clone), 'OO-style deep equality works');
     ok(!_.isEqual(5, NaN), '5 is not equal to NaN');
-	ok(NaN != NaN, 'NaN is not equal to NaN (native equality)');
-	ok(NaN !== NaN, 'NaN is not equal to NaN (native identity)');
+    ok(NaN != NaN, 'NaN is not equal to NaN (native equality)');
+    ok(NaN !== NaN, 'NaN is not equal to NaN (native identity)');
     ok(!_.isEqual(NaN, NaN), 'NaN is not equal to NaN');
     ok(_.isEqual(new Date(100), new Date(100)), 'identical dates are equal');
     ok(_.isEqual((/hello/ig), (/hello/ig)), 'identical regexes are equal');
     ok(!_.isEqual(null, [1]), 'a falsy is never equal to a truthy');
-    ok(!_.isEqual({x: 1, y: undefined}, {x: 1, z: 2}), 'object with the same number of undefined keys are not equal');
+    ok(!_.isEqual({x: 1, y: undefined}, {x: 1, z: 2}), 'objects with the same number of undefined keys are not equal');
+    ok(!_.isEqual(_({x: 1, y: undefined}).chain(), _({x: 1, z: 2}).chain()), 'wrapped objects are not equal');
+    equals(_({x: 1, y: 2}).chain().isEqual(_({x: 1, y: 2}).chain()).value(), true, 'wrapped objects are equal');
   });
 
   test("objects: isEmpty", function() {
diff --git a/underscore.js b/underscore.js
index 887d039c3..ca580fc2b 100644
--- a/underscore.js
+++ b/underscore.js
@@ -519,6 +519,9 @@
 
   // Perform a deep comparison to check if two objects are equal.
   _.isEqual = function(a, b) {
+    // Unwrap any wrapped objects
+    if (a && a._chain) a = a.value();
+    if (b && b._chain) b = b.value();
     // Check object identity.
     if (a === b) return true;
     // Different types?