how to restrict global variables or functions in node js

Question

how to restrict global variables or functions in node js

how to restrict global variables and functions in node js?

like: require method

i want to limit use of require method. i don't want any node app to access "fs" in my node framework which i build on top of express, they can only require modules which i want them to. and also i want to restrict access to process, global scope .

suppose when i load any js library for any app

like:

var x=require('app1.js');

in my framework

then i want to make sure this app1.js cannot access filesystem using require("fs")

app1.js

var x=require("fs");
exports.hello=function(){
   console.log(typeof x.readSync);
}

i want this console to print undefined;

and in this sample

var x=require("helper.js");
exports.hello=function(){
   console.log(typeof x.hello);
}

i want this console to print function;

thanks in advance

node.js
express

Answer 1

Why would you want to do that?

It is not possible to change the way require works, as it is a build-in node.js function.

Answer 2

I'd create a new function that will act like require.

requireSafe = function(param){
    if(!isAllowedLogic(param)) return null;
    else return require(param);
}

And when someone submits code, you append var require; at the top to prevent them to use the regular require. Or you search in their submission and only approve it if it doesn't contain require nor eval.