Fixing require?

Yomguithereal · Yomguithereal · commit 31cc1ee3baf3 · 2016-08-09T10:23:56.000+02:00
diff --git a/src/sigma.export.js b/src/sigma.export.js
@@ -5,11 +5,11 @@ var sigma = this.sigma,
 sigma.conrad = conrad;
 
 // Dirty polyfills to permit sigma usage in node
-if (HTMLElement === undefined)
-  var HTMLElement = function() {};
+if (typeof HTMLElement === 'undefined')
+  HTMLElement = function() {};
 
-if (window === undefined)
-  var window = {
+if (typeof window === 'undefined')
+  window = {
     addEventListener: function() {}
   };
 
