v.js

var vm = require('vm');

var code =
    'Object.defineProperty(this, "f", {\n' +
    '  get: function() { return x; },\n' +
    '  set: function(k) { x = k; },\n' +
    '  configurable: true,\n' +
    '  enumerable: true\n' +
    '});\n' +
    'g = f;\n' +
    // This line makes it work, by triggering the setter callback:
    // 'Object.keys(this).forEach(function(k){this[k]=this[k]});\n' +
    'f;\n';

var x = {};
var o = vm.createContext({ console: console, x: x });

var res = vm.runInContext(code, o, 'test');

console.error('res=%j f=%j res==x?%j res===f?%j keys=%j',
              res, o.f, res === x, res === o.f, Object.keys(o));