From 3524721b4d8f58a7643455cfa398bc235695470b Mon Sep 17 00:00:00 2001
From: Tyler Barnes <tylerdbarnes@gmail.com>
Date: Thu, 22 Nov 2018 16:51:56 -0800
Subject: [PATCH] check for session storage existance before trying to use it

---
 package.json     | 2 +-
 src/wrap-page.js | 7 +++++--
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/package.json b/package.json
index cf7ab33..4a91f51 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "gatsby-plugin-transition-link",
-  "version": "1.3.0",
+  "version": "1.3.1",
   "description": "A link component for page transitions in gatsby.",
   "repository": "/~https://github.com/TylerBarnes/gatsby-plugin-transition-link",
   "homepage": "https://gatsby-plugin-transition-link.netlify.com/",
diff --git a/src/wrap-page.js b/src/wrap-page.js
index 0793b90..776e751 100644
--- a/src/wrap-page.js
+++ b/src/wrap-page.js
@@ -5,7 +5,10 @@ const Consumer = require("./context/createTransitionContext").Consumer;
 
 // eslint-disable-next-line react/prop-types,react/display-name
 module.exports = ({ element, props }) => {
-  const minHeight = sessionStorage.getItem("wrapperMinHeight");
+  const sessionMinHeight =
+    typeof sessionStorage !== "undefined"
+      ? sessionStorage.getItem("wrapperMinHeight")
+      : false;
   return (
     <InternalProvider>
       <Consumer>
@@ -16,7 +19,7 @@ module.exports = ({ element, props }) => {
               zIndex: 0,
               minHeight: wrapperMinHeight
                 ? `${wrapperMinHeight}px`
-                : `${minHeight}px`
+                : `${!!sessionMinHeight ? sessionMinHeight + "px" : false}`
             }}
           >
             <TransitionHandler {...props}>{element}</TransitionHandler>