no-joke-wtf.js

'use strict';

function pTest(num){
  return new Promise((resolve, reject) => {
    process.nextTick(() => {
      resolve(++num);
    });
  });
}

run(function *gen(){
  var a = yield pTest(1);
  var b = yield pTest(a);
  var c = yield pTest(b);
  return [a, b, c];
}).then(function(result){
  console.log('done with run');
  console.log(result);
}).catch((err) => {
  console.error(err);
});

function run(genorator){
  var iter = genorator();
  try {
    return handle(iter.next());
  } catch(e){
    return Promise.reject(e);
  }

  function handle(gen){
    if (gen.done) {
      return Promise.resolve(gen.value);
    }
    return Promise.resolve(gen.value).then(function(res){
      console.log(res);
      return handle(iter.next(res));
    }).catch(function(err) {
      return handle(iter.throw(err));
    });
  };
};