<!DOCTYPE HTML> <html> <!-- https://bugzilla.mozilla.org/show_bug.cgi?id=1457051 --> <head> <meta charset="utf-8"> <title>Test for Bug 1457051</title> <script src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script> <link rel="stylesheet" type="text/css" href="chrome://global/skin"/> <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css"/> <script type="application/javascript"> /** Test for Bug 1457051 **/ ok(Element.isInstance(document.documentElement), "Basic isInstance works"); ok(!Element.isInstance(null), "Passing null should return false without throwing"); ok(!Element.isInstance(5), "Passing 5 should return false without throwing"); var obj = Object.create(Element.prototype); ok(obj instanceof Element, "instanceof should walk the proto chain"); ok(!Element.isInstance(obj), "isInstance should be a pure brand check"); </script> </head> <body> <a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1457051">Mozilla Bug 1457051</a> <p id="display"></p> <div id="content" style="display: none"> </div> <pre id="test"> </pre> </body> </html>