From 65f8da165455ac629d55c105d2898f531b15d7c5 Mon Sep 17 00:00:00 2001
From: John-David Dalton <john.david.dalton@gmail.com>
Date: Tue, 26 Jun 2012 03:23:53 -0400
Subject: [PATCH] Make `_.size` work consistently cross-browser with
 `arguments` objects and avoid erroring when falsey values are passed.

Former-commit-id: 76dc852a4e1fd84218f9c57f44c93e483a3680d9
---
 lodash.js    |  9 +++++----
 test/test.js | 16 +++++++++++++++-
 2 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/lodash.js b/lodash.js
index b89bd9582..4a0b2a72c 100644
--- a/lodash.js
+++ b/lodash.js
@@ -2918,10 +2918,11 @@
    * // => 5
    */
   function size(value) {
-    var className = toString.call(value);
-    return className == arrayClass || className == stringClass
-      ? value.length
-      : keys(value).length;
+    if (!value) {
+      return 0;
+    }
+    var length = value.length;
+    return length === length >>> 0 ? value.length : keys(value).length;
   }
 
   /**
diff --git a/test/test.js b/test/test.js
index 9b09ab0ff..b5bf59f77 100644
--- a/test/test.js
+++ b/test/test.js
@@ -582,14 +582,28 @@
   QUnit.module('lodash.size');
 
   (function() {
+    var args = arguments;
+
     test('should detect the size of a string value', function() {
       equal(_.size('abc'), 3);
     });
 
+    test('should allow a falsey `object` argument', function() {
+      try {
+        var actual = [_.size(), _.size(null), _.size(false), _.size(0)];
+      } catch(e) { }
+
+      deepEqual(actual, [0, 0, 0, 0]);
+    });
+
+    test('should work with `arguments` objects (test in IE < 9)', function() {
+      equal(_.size(args), 3);
+    });
+
     test('fixes the JScript [[DontEnum]] bug (test in IE < 9)', function() {
       equal(_.size(shadowed), 7);
     });
-  }());
+  }(1, 2, 3));
 
   /*--------------------------------------------------------------------------*/