From 0564f3e7bc6dd4de12206f4fb906c32b9255bd50 Mon Sep 17 00:00:00 2001
From: casperlamboo <casperlamboo@gmail.com>
Date: Thu, 20 Jul 2017 00:06:19 +0200
Subject: [PATCH] fix onProgress handling in slice function

---
 src/Slicer.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/Slicer.js b/src/Slicer.js
index fba0910..c4d9d34 100644
--- a/src/Slicer.js
+++ b/src/Slicer.js
@@ -52,7 +52,9 @@ export default class {
             break;
           }
           case 'PROGRESS': {
-            onProgress(data);
+            if (typeof onProgress !== 'undefined') {
+              onProgress(data);
+            }
             break;
           }
         }