From f9a27805468754f2e1927a8b95c0f18b01f97c50 Mon Sep 17 00:00:00 2001
From: Guillaume Beraudo <guillaume.beraudo@camptocamp.com>
Date: Wed, 28 Feb 2018 23:24:53 +0100
Subject: [PATCH] Do not assume window is defined

It is notably not the case in web workers.
---
 src/ol/index.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/ol/index.js b/src/ol/index.js
index f2e44acc19..377d594239 100644
--- a/src/ol/index.js
+++ b/src/ol/index.js
@@ -41,7 +41,7 @@ let WEBGL_EXTENSIONS; // value is set below
 let HAS_WEBGL = false;
 
 
-if ('WebGLRenderingContext' in window) {
+if (typeof window !== 'undefined' && 'WebGLRenderingContext' in window) {
   try {
     const canvas = /** @type {HTMLCanvasElement} */
         (document.createElement('CANVAS'));