<!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml" xmlns:xhtml="http://www.w3.org/1999/xhtml" lang="en" > <head> <script src="/resources/testharness.js"></script> <script src="/resources/testharnessreport.js"></script> </head> <body> <div id="default-namespace"></div> <xhtml:div id="explicit-namespace"></xhtml:div> <script> <![CDATA[ test(function() { const defaultNamespaceHost = document.getElementById('default-namespace'); defaultNamespaceHost.attachShadow({mode: 'open'}); assert_not_equals(defaultNamespaceHost.shadowRoot, null, "attachShadow should work on node with default namespace"); }, 'attachShadow with a default-namespaced element'); test(function() { const explicitNamespaceHost = document.getElementById('explicit-namespace'); explicitNamespaceHost.attachShadow({mode: 'open'}); assert_not_equals(explicitNamespaceHost.shadowRoot, null, "attachShadow should work on node with explicit namespace"); }, 'Test attachShadow with a namespaced element'); ]]> </script> </body> </html>