Run Bluebird Promises Sequentially, without return values?

Question

This question has been asked in a variety of ways, but not quite as simply.

How would this Promise.all be rewritten so that promise1 runs completely before promise2 ?

var promise1 = function() { .. lots of promise stuff };
var promise2 = function() { .. lots more promise stuff };

Promise.all([promise1, promise2]).then(function() {
  log.info("ran promise1 & promise2");
});

Promise.all runs promise1 & promise2 in parallel.

Answer 1

You can use Promise.map with concurrency option set to 1.

 var promise1 = function () { return new Promise(function (resolve, reject) { console.log("promise1 pending"); setTimeout(function () { console.log("promise1 fulfilled"); resolve(); }, 1000) }) }; var promise2 = function () { return new Promise(function (resolve, reject) { console.log("promise2 pending"); setTimeout(function () { console.log("promise2 fulfilled"); resolve() }, 50) }) }; Promise.map([promise1, promise2], function (promiseFn) { return promiseFn(); //make sure that here You return Promise }, {concurrency: 1}); //it will run promises sequentially //It logs //promise1 pending //promise 1 fulfilled //promise2 pending //promise 2 fulfilled 

Answer 2

Use then :

Returns a new promise chained from this promise.

promise1().then(function() {
  return promise2();
}).then(function() {
  log.info("ran promise1 & promise2");
});