What javascript library sets the _parsedUrl property on a request object

Question

I am working with node/express/passport/ looking at code that attempts to use a request like: req._parsedUrl.pathname;

I cannot figure out where this variable is coming from. Is this a canonical variable name that is set in a common .js library? It doesn't seem exposed in any headers.

Answer 1

req._parsedUrl is created by the parseurl library which is used by Express' Router when handling an incoming request.

The Router doesn't actually intend to create req._parsedUrl. Instead parseurl creates the variable as a form of optimization through caching.

If you want to use req._parsedUrl.pathname do the following instead in order to ensure that your server doesn't crash if req._parsedUrl is missing:

var parseUrl = require('parseurl');

function yourMiddleware(req, res, next) {
    var pathname = parseUrl(req).pathname;
    // Do your thing with pathname
}

parseurl will return req._parsedUrl if it already exists or if not it does the parsing for the first time. Now you get the pathname in a save way while still not parsing the url more than once.