check if function is a generator

Question

I played with generators in Nodejs v0.11.2 and I\'m wondering how I can check that argument to my function is generator function.

I found this way typeof f ===

Answer 1

function isGenerator(target) {
  return target[Symbol.toStringTag] === 'GeneratorFunction';
}

or

function isGenerator(target) {
  return Object.prototype.toString.call(target) === '[object GeneratorFunction]';
}