From d909d28e50d7012895cef2c75c0a50c56cbb8401 Mon Sep 17 00:00:00 2001
From: Rocky Meza <rocky@fusionbox.com>
Date: Sun, 15 Apr 2012 00:23:27 -0600
Subject: [PATCH] ensure that you can create durations from an actual duration
 object

---
 moment.js               | 10 ++++++++--
 test/moment/duration.js | 27 +++++++++++++++++++++++++++
 2 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/moment.js b/moment.js
index 476b29845..ea468625f 100644
--- a/moment.js
+++ b/moment.js
@@ -475,8 +475,9 @@
 
     // duration
     moment.duration = function (input, key) {
-        var isNumber = (typeof input === 'number'),
-            duration = isNumber ? {} : input;
+        var isDuration = moment.isDuration(input),
+            isNumber = (typeof input === 'number'),
+            duration = (isDuration ? input._data : (isNumber ? {} : input));
 
         if (isNumber) {
             if (key) {
@@ -579,6 +580,11 @@
         return obj instanceof Moment;
     };
 
+    // for typechecking Duration objects
+    moment.isDuration = function (obj) {
+        return obj instanceof Duration;
+    };
+
     // shortcut for prototype
     moment.fn = Moment.prototype = {
 
diff --git a/test/moment/duration.js b/test/moment/duration.js
index 6cab93a37..cd5aa40e5 100644
--- a/test/moment/duration.js
+++ b/test/moment/duration.js
@@ -65,6 +65,25 @@ exports.duration = {
         test.done();
     },
 
+    "instantiation from another duration" : function(test) {
+        var simple = moment.duration(1234),
+            complicated = moment.duration({
+                years: 2,
+                months: 3,
+                weeks: 4,
+                days: 1,
+                hours: 8,
+                minutes: 9,
+                seconds: 20,
+                milliseconds: 12
+            });
+
+        test.expect(2);
+        test.deepEqual(moment.duration(simple), simple, "simple clones are equal");
+        test.deepEqual(moment.duration(complicated), complicated, "complicated clones are equal");
+        test.done();
+    },
+
     "humanize" : function(test) {
         test.expect(32);
         moment.lang('en');
@@ -109,5 +128,13 @@ exports.duration = {
         test.equal(moment.duration({seconds:  44}).humanize(true),  "in a few seconds", "44 seconds = a few seconds");
         test.equal(moment.duration({seconds: -44}).humanize(true),  "a few seconds ago", "44 seconds = a few seconds");
         test.done();
+    },
+
+    "isDuration" : function(test) {
+        test.expect(3);
+        test.ok(moment.isDuration(moment.duration(12345678)), "correctly says true");
+        test.ok(!moment.isDuration(moment()), "moment object is not a duration");
+        test.ok(!moment.isDuration({milliseconds: 1}), "plain object is not a duration");
+        test.done();
     }
 };
-- 
2.47.3