/*! { "name": "ES5 Immutable Undefined", "property": "es5undefined", "notes": [{ "name": "ECMAScript 5.1 Language Specification", "href": "https://www.ecma-international.org/ecma-262/5.1/" }, { "name": "original implementation of detect code", "href": "https://kangax.github.io/compat-table/es5/" }], "authors": ["Ron Waldon (@jokeyrhyme)"], "tags": ["es5"] } !*/ /* DOC Check if browser prevents assignment to global `undefined` per ECMAScript 5. */ define(['Modernizr'], function(Modernizr) { Modernizr.addTest('es5undefined', function() { var result, originalUndefined; try { originalUndefined = window.undefined; window.undefined = 12345; result = typeof window.undefined === 'undefined'; window.undefined = originalUndefined; } catch (e) { return false; } return result; }); });