Clean Array.prototype pollution in Javascript/Node.js

proto-clean.js

Array.prototype.foo = function() { return 'Still callable'; };

function test() {
  let count = 0;
  for (const e in []) {
    console.log('Found '+e);
    count++;
    Object.defineProperty(Array.prototype, e, {
      value: Array.prototype[e],
      enumerable: false
    });
  }
  if (!count) console.log('All clean');
}

test();
test();
console.log([].foo());