973988 - DOM Promise constructor should call the executor with `undefined` as thisArg

Status: RESOLVED FIXED

(Core :: DOM: Core & HTML, defect)

Description

[Brandon Benvie [:benvie]]

> "use strict";
> new Promise(() => assert(this === undefined));

Currently this test fails in our implementation. |this| in the executor is the new Promise object itself, rather than undefined.

See ES6 spec draft January 2014 revision section 25.4.3.1.1 InitialisePromise, step 8.

Comment 1

[:Ms2ger (he/him; ⌚ UTC+1/+2)]

'this' in an arrow function doesn't work how you think it works.

Comment 2

[Brandon Benvie [:benvie]]

Woops, my example was incorrect but what I said is right:

> new Promise(function(){ console.log(this) }); // [object Promise]

Comment 3

[Boris Zbarsky [:bzbarsky]]

William, can you take a look please?

Comment 4

[William Chen [:wchen]]

Looking into it.

Comment 5

[William Chen [:wchen]]

Attachment: DOM Promise constructor should call the executor with "undefined" as thisArg

Comment 6

[Boris Zbarsky [:bzbarsky]]

Comment on attachment 8377951 [details] [diff] [review]
DOM Promise constructor should call the executor with "undefined" as thisArg

r=me assuming the spec is clear on this and whatnot.

Comment 7

[William Chen [:wchen]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/5c6b2dcd79eb

Comment 8

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/5c6b2dcd79eb