_equals(element.firstChild.namespaceURI, "someNamespace");
    assert_equals(element.lastChild.prefix, 'html');
    assert_equals(element.lastChild.namespaceURI, "http://www.w3.org/1999/xhtml");
}, "Setting innerHTML on a HTML element with a non-HTML namespace as the default namespace");

test(() => {
    const element = document.getElementById("target");
    element.outerHTML = '<b /><html:b />';
    assert_equals(element.firstChild.prefix, null);
    assert_equals(element.firstChild.namespaceURI, "someNam