From 65352e0da25500701e1256e382e1f4dfa24d31c0 Mon Sep 17 00:00:00 2001
From: Lucas Sanders <butterflyhug@google.com>
Date: Sun, 30 Oct 2016 14:27:56 -0400
Subject: [PATCH] Remove _bubble() from Duration prototype and make its API
 immutable

The bubble function now returns a new data object instead of
mutating the duration's existing data (which had always been empty
when we called _bubble anyway).
---
 src/lib/duration/bubble.js      | 13 ++++++-------
 src/lib/duration/constructor.js |  7 +++----
 src/lib/duration/prototype.js   |  1 -
 3 files changed, 9 insertions(+), 12 deletions(-)

diff --git a/src/lib/duration/bubble.js b/src/lib/duration/bubble.js
index 0c4a336ec..f24ec5c5d 100644
--- a/src/lib/duration/bubble.js
+++ b/src/lib/duration/bubble.js
@@ -2,11 +2,11 @@ import absFloor from '../utils/abs-floor';
 import absCeil from '../utils/abs-ceil';
 import { createUTCDate } from '../create/date-from-array';
 
-export function bubble () {
-    var milliseconds = this._milliseconds;
-    var days         = this._days;
-    var months       = this._months;
-    var data         = this._data;
+export function bubble (duration) {
+    var milliseconds = duration._milliseconds;
+    var days         = duration._days;
+    var months       = duration._months;
+    var data         = {};
     var seconds, minutes, hours, years, monthsFromDays;
 
     // if we have a mix of positive and negative values, bubble down first
@@ -45,8 +45,7 @@ export function bubble () {
     data.days   = days;
     data.months = months;
     data.years  = years;
-
-    return this;
+    return data;
 }
 
 export function daysToMonths (days) {
diff --git a/src/lib/duration/constructor.js b/src/lib/duration/constructor.js
index 5c97ef108..578ba34f6 100644
--- a/src/lib/duration/constructor.js
+++ b/src/lib/duration/constructor.js
@@ -1,6 +1,7 @@
 import { normalizeObjectUnits } from '../units/aliases';
 import { getLocale } from '../locale/locales';
-import isDurationValid from './valid.js';
+import { bubble } from './bubble';
+import isDurationValid from './valid';
 
 export function Duration (duration) {
     var normalizedInput = normalizeObjectUnits(duration),
@@ -32,11 +33,9 @@ export function Duration (duration) {
         quarters * 3 +
         years * 12;
 
-    this._data = {};
+    this._data = bubble(this);
 
     this._locale = getLocale();
-
-    this._bubble();
 }
 
 export function isDuration (obj) {
diff --git a/src/lib/duration/prototype.js b/src/lib/duration/prototype.js
index 3fd516a56..7eaca4461 100644
--- a/src/lib/duration/prototype.js
+++ b/src/lib/duration/prototype.js
@@ -27,7 +27,6 @@ proto.asWeeks        = asWeeks;
 proto.asMonths       = asMonths;
 proto.asYears        = asYears;
 proto.valueOf        = valueOf;
-proto._bubble        = bubble;
 proto.get            = get;
 proto.milliseconds   = milliseconds;
 proto.seconds        = seconds;
-- 
2.47.2