var express = require('express');

var app = express();
var myObj = {}

app.get('/user/:id', function(req, res) {
	myCoolLocalFct(req.query.userControlled);
	var prop = myCoolLocalFct(req.query.userControlled);    
	myObj[prop] = 23; // NOT OK
	myObj.prop = 23; // OK
	var x = myObj[prop]; // NOT OK
	x(23);	
	delete myObj[prop]; // NOT OK	
	Object.defineProperty(myObj, prop, {value: 24}); // NOT OK
	var headers = {};	
	headers[prop] = 42; // NOT OK
	res.set(headers);	
});

function myCoolLocalFct(x) {
	var result = x;
	return result.substring(0, result.length);
	
}