npm and error messages

node_modules/es5-ext/object/ensure-array.js

@@ -0,0 +1,9 @@
+"use strict";
+
+var toShortString = require("../to-short-string-representation")
+  , isArray       = require("./is-array-like");
+
+module.exports = function (value) {
+	if (isArray(value)) return value;
+	throw new TypeError(toShortString(value) + " is not a array");
+};