From 5efbb3f601209e238f4ae63ef4073975da82f611 Mon Sep 17 00:00:00 2001
From: tomerle <tomerle@users.noreply.github.com>
Date: Tue, 15 Sep 2020 18:26:34 +0300
Subject: [PATCH] [misc] Use switch-case for better get-set performance (#2659)

Also done for `setMonth`.
Also simplified Leap Day logic.
---
 src/lib/moment/get-set.js | 85 +++++++++++++++++++++++++++++----------
 src/lib/units/month.js    | 11 +++--
 2 files changed, 70 insertions(+), 26 deletions(-)

diff --git a/src/lib/moment/get-set.js b/src/lib/moment/get-set.js
index cbdd45520..d6a7f6690 100644
--- a/src/lib/moment/get-set.js
+++ b/src/lib/moment/get-set.js
@@ -2,9 +2,7 @@ import { normalizeUnits, normalizeObjectUnits } from '../units/aliases';
 import { getPrioritizedUnits } from '../units/priorities';
 import { hooks } from '../utils/hooks';
 import isFunction from '../utils/is-function';
-import { daysInMonth } from '../units/month';
-import { isLeapYear } from '../utils/is-leap-year';
-import toInt from '../utils/to-int';
+import { isLeapYear } from '../units/year';
 
 export function makeGetSet(unit, keepTime) {
     return function (value) {
@@ -19,29 +17,72 @@ export function makeGetSet(unit, keepTime) {
 }
 
 export function get(mom, unit) {
-    return mom.isValid()
-        ? mom._d['get' + (mom._isUTC ? 'UTC' : '') + unit]()
-        : NaN;
+    if (!mom.isValid()) {
+        return NaN;
+    }
+
+    var d = mom._d,
+        isUTC = mom._isUTC;
+
+    switch (unit) {
+        case 'Milliseconds':
+            return isUTC ? d.getUTCMilliseconds() : d.getMilliseconds();
+        case 'Seconds':
+            return isUTC ? d.getUTCSeconds() : d.getSeconds();
+        case 'Minutes':
+            return isUTC ? d.getUTCMinutes() : d.getMinutes();
+        case 'Hours':
+            return isUTC ? d.getUTCHours() : d.getHours();
+        case 'Date':
+            return isUTC ? d.getUTCDate() : d.getDate();
+        // case 'Day': return isUTC ? d.getUTCDay() : d.getDay(); // Not used
+        case 'Month':
+            return isUTC ? d.getUTCMonth() : d.getMonth();
+        case 'FullYear':
+            return isUTC ? d.getUTCFullYear() : d.getFullYear();
+        default:
+            return NaN; // Just in case
+    }
 }
 
 export function set(mom, unit, value) {
-    if (mom.isValid() && !isNaN(value)) {
-        if (
-            unit === 'FullYear' &&
-            isLeapYear(mom.year()) &&
-            mom.month() === 1 &&
-            mom.date() === 29
-        ) {
-            value = toInt(value);
-            mom._d['set' + (mom._isUTC ? 'UTC' : '') + unit](
-                value,
-                mom.month(),
-                daysInMonth(value, mom.month())
-            );
-        } else {
-            mom._d['set' + (mom._isUTC ? 'UTC' : '') + unit](value);
-        }
+    var d, isUTC, year, month, date;
+
+    if (!mom.isValid() || isNaN(value)) {
+        return;
     }
+
+    d = mom._d;
+    isUTC = mom._isUTC;
+
+    switch (unit) {
+        case 'Milliseconds':
+            return void (isUTC
+                ? d.setUTCMilliseconds(value)
+                : d.setMilliseconds(value));
+        case 'Seconds':
+            return void (isUTC ? d.setUTCSeconds(value) : d.setSeconds(value));
+        case 'Minutes':
+            return void (isUTC ? d.setUTCMinutes(value) : d.setMinutes(value));
+        case 'Hours':
+            return void (isUTC ? d.setUTCHours(value) : d.setHours(value));
+        case 'Date':
+            return void (isUTC ? d.setUTCDate(value) : d.setDate(value));
+        // case 'Day': return void (isUTC ? d.setUTCDay(value) : d.setDay(value)); // Not real
+        // case 'Month': return void (isUTC ? d.setUTCMonth(value) : d.setMonth(value)); // Not used
+        case 'FullYear':
+            break; // See below ...
+        default:
+            return; // Just in case
+    }
+
+    year = value;
+    month = mom.month();
+    date = mom.date();
+    date = date === 29 && month === 1 && !isLeapYear(year) ? 28 : date;
+    void (isUTC
+        ? d.setUTCFullYear(year, month, date)
+        : d.setFullYear(year, month, date));
 }
 
 // MOMENTS
diff --git a/src/lib/units/month.js b/src/lib/units/month.js
index a2b90cb34..9a326aa33 100644
--- a/src/lib/units/month.js
+++ b/src/lib/units/month.js
@@ -218,8 +218,6 @@ export function localeMonthsParse(monthName, format, strict) {
 // MOMENTS
 
 export function setMonth(mom, value) {
-    var dayOfMonth;
-
     if (!mom.isValid()) {
         // No op
         return mom;
@@ -237,8 +235,13 @@ export function setMonth(mom, value) {
         }
     }
 
-    dayOfMonth = Math.min(mom.date(), daysInMonth(mom.year(), value));
-    mom._d['set' + (mom._isUTC ? 'UTC' : '') + 'Month'](value, dayOfMonth);
+    var month = value,
+        date = mom.date();
+
+    date = date < 29 ? date : Math.min(date, daysInMonth(mom.year(), month));
+    void (mom._isUTC
+        ? mom._d.setUTCMonth(month, date)
+        : mom._d.setMonth(month, date));
     return mom;
 }
 
-- 
2.47.2