Pretty print JSON nodes from XQuery in MarkLogic (>=8)

json-stringify.xqy

(: NOTE: In a production system you should amp json:stringify to avoid arbitrary JavaScript execution. :)
declare function json:stringify($json as node(), $spaces as xs:int) as xs:string? {
 xdmp:javascript-eval("JSON.stringify($json.toObject(), null, $spaces)", ('$json', $json, '$spaces', $spaces))
};

declare function json:stringify($json as node()) as xs:string? {
 json:stringify($json, 2)
};

let $node := xdmp:unquote('["B", "B"]')
let $node := <asdf/> (: returns empty-sequence() :)
let $node := xdmp:unquote('{"a": "A", "b": ["B", "B"]}')
return json:stringify($node)

(:
=>

'
{
 "a": "A",
 "b": [
   "B",
   "B"
 ]
}
'
:)