1168260 - Promise constructor methods should not be enumerable

Status: RESOLVED FIXED

(Core :: JavaScript: Standard Library, defect)

Description

[ljharb]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_3) AppleWebKit/600.6.3 (KHTML, like Gecko) Version/8.0.6 Safari/600.6.3

Steps to reproduce:

`Object.keys(Promise).length === 0 && !['resolve', 'reject', 'all', 'race'].map(k => Promise.propertyIsEnumerable(k)).some(Boolean)`


Actual results:

`false`


Expected results:

`true`

Comment 1

[Benjamin Bouvier [:bbouvier] (inactive)]

As of today, Promises in Firefox are implemented on the DOM side, not in JS.

Comment 2

[Boris Zbarsky [:bzbarsky]]

We could add something in Web IDL to make things non-enumerable.... or we could just wait until SpiderMonkey in fact implements promises like it should.  Unless there's an urgent need to fix this, I would rather just do the latter.

That said, Cameron, are there any plans to add a way to annotate things as non-enumerable in IDL?

Comment 3

[Cameron McCormack (:heycam)]

(In reply to Not doing reviews right now from comment #2)
> That said, Cameron, are there any plans to add a way to annotate things as
> non-enumerable in IDL?

No plans to add this currently.  Of course, that doesn't need to affect whether we support such a way in our bindings so that we can fix these Promise methods.

Comment 4

[Claude Pache]

This bug was filed for constructor methods, but the exact same issue exists for instance methods:

    Object.keys(Promise.prototype).length // should be 0, is currently 2

Comment 5

[Boris Zbarsky [:bzbarsky]]

Yes, it's the exact same issue.  The difference between ES6 builtins and web platform builtins in this regard is quite vexing.

Comment 6

[Tom S [:evilpie]]

Fixed with bug 911216:

js> Object.keys(Promise.prototype).length
0
js> Object.keys(Promise).length           
0

Comment 7

[Masatoshi Kimura [:emk]]

Why is this bug (and bug 1237762) still open?

Comment 8

[Tom S [:evilpie]]

Attachment: Test: Promise methods are not enumerable

Comment 9

[Till Schneidereit [:till]]

Comment on attachment 8778172 [details] [diff] [review]
Test: Promise methods are not enumerable

Review of attachment 8778172 [details] [diff] [review]:
-----------------------------------------------------------------

Thank you.

Comment 10

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/ab210b9e2172
Test: Promise methods should not be enumerable. r=till

Comment 11

[Phil Ringnalda (:philor)]

https://hg.mozilla.org/mozilla-central/rev/ab210b9e2172