Errors not thrown

[codepunkt]

Chrome 41 throws uncatched errors using native window.Promise:

new window.Promise(function(res, rej) {
  throw new Error('window.Promise');
});

The only way i can achieve this behavior using es6-promise is by re-throwing in a setTimeout in catch:

var Promise = require('es6-promise');

new Promise(function(res, rej) {
  throw new Error('es6-promise');
}).catch(function(err) {
  setTimeout(function() {
    throw err;
  }, 0);
});

This is not developer-friendly at all.
While i've read #70, #71 and especially #40 i don't get how this is specced behavior. Can't find anything in the current ES6 draft on this.

Maybe someone can shed a little light.

[stefanpenner]

Chrome actually doesn't throw them, rather an unspeced log. I agree it would be good to add that back to this project.

[allanhortle]

Bump. This is strange behaviour.

[jakearchibald]

Throwing via setTimeout isn't the right solution here - as Stefan points
out Chrome's doing a simple log, whereas a throw will bubble up to
window.onerror.

On Tue, 31 Mar 2015 00:49 Allan Hortle [email protected] wrote:

Bump. This is strange behaviour.

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#88 (comment)
.

[stefanpenner]

I've been saturated with other OSS responsibilities, but I will circle around and push this forward :)

[juandopazo]

@stefanpenner I can help.

So one way to do this would be:

1. On Reject, if there are no error handlers do promise.__errorLogTimeout = setTimeout(() => console.error(error), 5000)
2. On then/catch, clearTimeout(promise.__errorLogTimeout).

[stefanpenner]

So one way to do this would be:

On Reject, if there are no error handlers do promise.__errorLogTimeout = setTimeout(() => console.error(error), 5000)
On then/catch, clearTimeout(promise.__errorLogTimeout).

awesome, but its has a few more requirements.

I have implemented something (quick and dirty) that closely mimics (but doesn't quite match) the expected heuristics. in RSVP (the parent project) https://github.com/tildeio/rsvp.js/blob/master/lib/rsvp/promise.js#L176-L182

It would actually be easier to implement it more heuristically correct in this project, as the async isn't pluggable as it is in ember.

So basically, Errors are logged only if not handled before the next macroTask. So their is a concise window where errors need to be handled, and where errors need to be logged.

[juandopazo]

Don't you think "the next macrotask" is too soon?

[stefanpenner]

Don't you think "the next macrotask" is too soon?

i don't believe so, we really need the browsers to give us access to their new promise pane....

[stefanpenner]

@domenic share your thoughts?

[domenic]

I'd just log on next macrotask and log again when it's caught. Chrome still is implementing the last part.

[stefanpenner]

duplicate: #70

[stefanpenner]

@domenic

Chrome still is implementing the last part.

the last part being, giving userland promises access to the new promise pane?

[domenic]

No, greying out the log when the rejection gets handled.

[stefanpenner]

@domenic lame :P

[ysmood]

Event Chrome and Bluebird is not good enough for me. I wrote mine, see the comparison: https://github.com/ysmood/yaku/blob/master/docs/debugHelperComparison.md

For more details: https://github.com/ysmood/yaku