So what I am trying to do is as take a javascript code as input from user and return him the result. Right now I am executing the code submitted by user just using eval (with some safety checks). But I understand this is highly unreliable. So what I want to achieve is run this in sandbox environment safely and return the result to user. E.g
Input:
var a =[1,2,3];
a.map(n => n*2);
Output:
[2,4,6]
I tried using vm in node but I don't really understand how to get the final result from it.
I tried using vm in node but I don't really understand how to get the final result from it.
Many vm module functions, like vm.runInNewContext(), will return the result of the last statement in the string, similar to eval().
var vm = require('vm');
var script = 'var a = [1, 2, 3]; a.map(n => n * 2);';
var sandbox = {};
var result = vm.runInNewContext(script, sandbox);
console.log(sandbox); // { a: [1, 2, 3] }
console.log(result); // [2, 4, 6]
An example of capturing the result is given in the description for vm.runInThisContext()
child_process module. If you can save the user's input to a file, then it can be run with child_process.fork(). To receive the result, you can require the script to .send() it – how to send message to parent process