So siehts ganz gut aus !

node_modules/es5-ext/string/#/ends-with/shim.js

@@ -0,0 +1,18 @@
+"use strict";
+
+var toInteger = require("../../../number/to-integer")
+  , value     = require("../../../object/valid-value")
+  , isValue   = require("../../../object/is-value")
+  , min       = Math.min
+  , max       = Math.max;
+
+module.exports = function (searchString /*, endPosition*/) {
+	var self, start, endPos;
+	self = String(value(this));
+	searchString = String(searchString);
+	endPos = arguments[1];
+	start =
+		(isValue(endPos) ? min(max(toInteger(endPos), 0), self.length) : self.length) -
+		searchString.length;
+	return start < 0 ? false : self.indexOf(searchString, start) === start;
+};