Infinite loop when generating local entropy

[josdejong]

I stumbled upon an issue where calling seed() causes an (almost) infinite recursive loop:

• seed() is called without arguments, in which case it uses a local entropy. This entropy is generated (amongst others) from all globally defined objects.
• seed() is called via a getter on an object which is globally defined (obj.random in the example).
• hence, when creating the local entropy, seed calls the obj.random getter which calls seed again -> infinite loop

node.js example code:

var seed = require('seed-random');

var count = 0;

// create an object
var obj = {};

// expose the object globally
global.obj = obj;

Object.defineProperty(obj, 'random', {
  get: function () {
    console.log('obj.random getter');
    count++;

    // call seed inside a getter of the globally defined object
    return seed();
  },
  configurable: true,
  enumerable: true
});

// call the getter... will cause an (almost) infinite loop
var a = obj.random();
console.log('a', a);

console.log('number of recursive loops over obj.random (should be 1):', count); 
// outputs for example count = 1425

Some ideas for a solution:

• Ignore properties which are getters when creating local entropy
• Output an informative warning when this loop happens (check whether seed is called whilst it's being executed)
• Throw an error when seed is called whilst it is being executed, and when generating local entropy, catch this error and silently ignore it.