How define function in javascript in global context inside a function?

Question

context = this
function test() {
  (function(cmd) {
    eval(cmd);
  }).call(context, 'function foo(){}');
};

test();
foo(); // => ReferenceError: foo is not defined

how can I define a global function inside a function ? (using nodeJS)

Answer 1

A typical way to access the global object is calling a yielded value, eg from the comma operator.

 function a() { (0, function () { this.foo = function () { console.log("works"); }; })(); } a(); foo(); 

UPDATE: Due to strict mode issues, here is another version (references: (1,eval)('this') vs eval('this') in JavaScript? , Cases where 'this' is the global Object in Javascript ):

 "use strict"; function a() { (0, eval)('this').foo = function () { console.log("works"); }; } a(); foo(); 

Answer 2

Use the global object in Node.JS:

function test() {
  eval('function foo() { return "this is global"; }');
  global.foo = foo;
};

test();

console.log(foo()); // this is global