From bdf253992c52e32b67eb1bb2f4d1ee3ceb13c7ab Mon Sep 17 00:00:00 2001
From: Marc Schipperheyn <m.schipperheyn@gmail.com>
Date: Mon, 22 Jun 2020 03:23:51 -0300
Subject: [PATCH] fix NaN on mount (#1193)

---
 src/index.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/index.js b/src/index.js
index 71de43a6..da429c2a 100644
--- a/src/index.js
+++ b/src/index.js
@@ -464,7 +464,7 @@ export default class extends Component {
     if (!this.internals.offset)
       // Android not setting this onLayout first? https://github.com/leecade/react-native-swiper/issues/582
       this.internals.offset = {}
-    const diff = offset[dir] - this.internals.offset[dir]
+    const diff = offset[dir] - (this.internals.offset[dir] || 0)
     const step = dir === 'x' ? state.width : state.height
     let loopJump = false