Serialize XML declaration

[xmedeko]

The XML declaration is not serialized, try the code:

let doc = new window.DOMParser().parseFromString('<?xml version="1.0" encoding="utf-8" standalone="yes"?><a>Ahoy</a>', 'application/xml');
console.log(new window.XMLSerializer().serializeToString(doc));

Chrome output: <?xml version="1.0" encoding="utf-8" standalone="yes"?><a>Ahoy</a>
jsdom 15.1.1, w3c-xmlserializer 1.1.2 output: <a>Ahoy</a>

[yingted]

You can work around it like this:

let doc = new window.DOMParser().parseFromString('<a>Ahoy</a>', 'application/xml');
doc.insertBefore(doc.createProcessingInstruction('xml', 'version="1.0" encoding="utf-8" standalone="yes"'), doc.firstChild);
console.log(new window.XMLSerializer().serializeToString(doc));

[xmedeko]

@yingted I just do a simple workaround:

let str = new window.XMLSerializer().serializeToString(doc);
if (!str.startsWith("<?xml"))
    str = '<?xml version="1.0" encoding="utf-8" standalone="yes"?>' + str;