This website's XML Pretty-Print utility uses the following code to convert JSON text into ready-to-read XML. Obviously, pretty-data is doing all the work. The second argument to the xml function specifies whether or not to retain XML comments.

var pd = require('pretty-data');

exports.prettyPrint = function(source) {
    return pd.pd.xml(source, true);
};

I am pretty and well-formed!