Async Loop With Generators and Promises

index.js

'use strict';

// async function (eg: rest call)
const makeRequest = function (endpoint) {
  return new Promise(function (resolve, reject) {
    resolve(endpoint);
  });
}

// generator function
// iterates over an array and call several time the async function
const generator = function* (resources) {
  for(let endpoint of resources){
    let foo = yield makeRequest(endpoint);
    console.log(foo);
  }
};

// Instantiate the generator,
// call next passing the value when the promise has been resolved,
// untill the generator has completed, then return the last promise value,
const run = function(generator, resources) {
  var it = generator(resources);

  function go(res){

    // if the generator has ended return the value
    if(res.done){
      return res.value;
    }

    //else wait for promise and call generators.next()
    return res.value
      .then((res) => {
        go(it.next(res));
      })
      .catch((e) => {
        it.throw(e);
      });
  }

  go(it.next());
}

// execution
const resources = ['endpont1', 'endpoint2', 'endpoint3'];

run(generator, resources);