Node.js url.parse result back to string

The other answer is good, but you could also do something like this. The querystring module is used to work with query strings.

var querystring = require('querystring');
var qs = querystring.parse(parts.query);
qs.page = 25;
parts.search = '?' + querystring.stringify(qs);
var newUrl = url.format(parts);

Seems to me like it's a bug in node. You might try

// in requires
var url = require('url');
var qs = require('querystring');

// later
var parts = url.parse(req.url, true);
parts.query['page'] = 25;
parts.query = qs.stringify(parts.query);
console.log("Link: ", url.format(parts));

If you look at the latest documentation, you can see that url.format behaves in the following way:

• search will be used in place of query
• query (object; see querystring) will only be used if search is absent.

And when you modify query, search remains unchanged and it uses it. So to force it to use query, simply remove search from the object:

var url = require("url");
var parts = url.parse("http://test.com?page=25&foo=bar", true);
parts.query.page++;
delete parts.search;
console.log(url.format(parts)); //http://test.com/?page=26&foo=bar

Make sure you're always reading the latest version of the documentation, this will save you a lot of trouble.