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

TJ Holowaychuk's co library has the best function for checking whether something is a generator function. Here is the source code:

function isGeneratorFunction(obj) {
   var constructor = obj.constructor;
   if (!constructor) return false;
   if ('GeneratorFunction' === constructor.name || 'GeneratorFunction' === constructor.displayName) return true;
   return isGenerator(constructor.prototype);
}

Reference: https://github.com/tj/co/blob/717b043371ba057cb7a4a2a4e47120d598116ed7/index.js#L221