From e19a4d2fdb946a7f868c74c221bf58e97a3abe41 Mon Sep 17 00:00:00 2001
From: Vladimir Kharlampidi <nolimits4web@gmail.com>
Date: Tue, 31 Jul 2018 14:40:58 +0300
Subject: [PATCH] Emit event immediately if only 1 mutation

Ref #2731
---
 src/modules/observer/observer.js | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/modules/observer/observer.js b/src/modules/observer/observer.js
index 023e03051..26eabb70c 100644
--- a/src/modules/observer/observer.js
+++ b/src/modules/observer/observer.js
@@ -12,6 +12,10 @@ const Observer = {
       // The observerUpdate event should only be triggered
       // once despite the number of mutations.  Additional
       // triggers are redundant and are very costly
+      if (mutations.length === 1) {
+        swiper.emit('observerUpdate', mutations[0]);
+        return;
+      }
       const observerUpdate = function observerUpdate() {
         swiper.emit('observerUpdate', mutations[0]);
       };