Possible reflection issue in .each() and .filter() ?

[iaean]

Running the following snippet (see the full gist) via node

p0.then(function() {
  var p1 = delayResolve(500);
  var p2 = delayReject(300);
  var p3 = delayResolve(400);
  return Promise.all([p1,p2,p3].map(function(p) { return p.reflect(); })) })
.each(function(p) {
  return p.isFulfilled() ? p.value() : null; })
.then(function(r) {
  console.log(JSON.stringify(r)); });

results in

[{"_bitField":268435457,"_settledValue":500},
 {"_bitField":135266305,"_settledValue":300},
 {"_bitField":268435457,"_settledValue":400}]

other than the expected [500,null,400] produced by .map().

Is this a bug in bluebird's node branch or do I something wrong in composition?

I'm always excited to hear from you.
Best regards

[benjamingr]

each does not mutate the value of a promise resolution. It iterates your array and then returns the original input. Did you want to use another map?

[benjamingr]

Or mapSeries if you want "sequential" behavior.

[iaean]

@benjamingr, thanks a lot for your reply. The sequential pattern via .mapSeries() is exactly what I need, but unfortunately replacing .each() with .mapSeries() in the block above throws: TypeError: p0.then(...).mapSeries is not a function. See the stack trace at the end of this gist...

[benjamingr]

Make sure you're using a recent version of bluebird it's relatively new.

Here is a working example http://bluebirdjs.com/docs/api/promise.mapseries.html

I can't read your code your placement of }) is very strange :P

[iaean]

@benjamingr, hoping it's better now...
bluebird@3.3.1 and node@4.2.6 resulting in TypeError: p0.then(...).mapSeries is not a function.

p0.then(function() {
  var p1 = delayResolve(500);
  var p2 = delayReject(300);
  var p3 = delayResolve(400);
  // resolved on settleAll (http://bluebirdjs.com/docs/api/reflect.html)
  return Promise.all([p1,p2,p3].map(function(p) {
    return p.reflect(); }));
})
.mapSeries(function(p) {
  return p.isFulfilled() ? p.value() : null;
})
.then(function(r) {
  console.log(JSON.stringify(r));
});

[petkaantonov]

p0 is probably a native promise which doesn't have mapSeries, only then and catch.

[iaean]

No. It's a bluebird promise instanced as

var p0 = delayResolve(200);

or

var p0 = Promise.resolve(delayResolve(200));

with

var Promise = require('bluebird');

function delayResolve(t) {
  return new Promise(function(resolve, reject) {
    setTimeout(function() { resolve(t); }, t); }); }

function delayReject(t) {
  return new Promise(function(resolve, reject) {
    setTimeout(function() { reject(t); }, t); }); }

I could provide a small gist to reproduce that issue...

[petkaantonov]

right after you require bluebird, can you log what Promise.prototype.mapSeries is?

[iaean]

@petkaantonov: ùndefined Here is a new gist...

[petkaantonov]

In that case you are requiring different bluebird version than you think you are

[iaean]

Oh, damn stupid... You are so right!
Sorry for confusion and thanks a lot for your guidance and investigation.
Best regards