Advance to stage 4

[mathiasbynens]

Criteria taken from the TC39 process document minus those from previous stages:

• Test262 acceptance tests have been written for mainline usage scenarios, and merged.

https://github.com/tc39/test262/tree/master/src/top-level-await

• Two compatible implementations which pass the acceptance tests

https://github.com/tc39/proposal-top-level-await#implementations

Bug tickets to track:

• Chrome/V8: https://bugs.chromium.org/p/v8/issues/detail?id=9344
• Edge/Chakra: Implement Top-Level Await (Stage 3 proposal) chakra-core/ChakraCore#6262
• Firefox/SpiderMonkey: https://bugzilla.mozilla.org/show_bug.cgi?id=1519100
• Safari/JavaScriptCore: https://bugs.webkit.org/show_bug.cgi?id=202484

• Significant in-the-field experience with shipping implementations, such as that provided by two independent VMs

TODO

• A pull request has been sent to https://github.com/tc39/ecma262 with the integrated spec text

TODO

• The ECMAScript editor has signed off on the pull request

tc39/ecma262#2408

[jhpratt]

Firefox/SpiderMonkey tracking issue: https://bugzilla.mozilla.org/show_bug.cgi?id=1519100

[TheInvoker]

when will this feature come out in chrome?

[MylesBorins]

@TheInvoker the issue is mentioned above on the chromium tracker. That issue will be updated as progress is made. I would not expect it in the near future.

[devsnek]

I was able to implement this in engine262 (engine262/engine262@c88172c) using a combination of the current spec text, #122, #123, and tc39/proposal-dynamic-import#71

[chicoxyzzy]

Implemented in V8 under flag #129

[TheInvoker]

Any idea on release date now?

[MylesBorins]

Added the webkit bug and test262 tests. AFAIK the tests are done @leobalter can confirm

[rhuanjl]

Chakracore issue: chakra-core/ChakraCore#6262

I have a WIP implementation for CC - just need a bit more testing and a re-factor it depends on to be merged. Will hopefully land it in CC's master in a week or two; I don't know when they'll do a release to include it though. (I'm an external contributor)

[leobalter]

this is a simple but almost formal confirmation of Test262 tests for TLA.

[NemoStein]

AFAICT Chrome released this feature (enabled by defaut) in Chrome 89 (V8 Ticket 9344 #50, ChromeStatus)
Node.js unflagged TLA since v14.8.0

Does this count as 2 implementations and/or independent VMs?

[rhuanjl]

As an FYI I've implemented this in ChakraCore master: chakra-core/ChakraCore#6457
(ChakraCore is no longer used by Edge and is now a Community project - we're hoping to release a version with significant enhancements since the last Microsoft release - adding top level await is one such - but we have a lot to do before we're ready for a release and don't have a date set yet)

[MylesBorins]

@NemoStein I don't think that it will as Node.js embeds V8

[mahnunchik]

I'm looking forward for stage 4 😄

[NemoStein]

It seems that all listed VMs/browsers already delivers TLA unflagged

V8 Chromium (Chrome/Edge/Opera): 89 - latest
SpiderMonkey Firefox: 89 beta
JavaScriptCore Safari: TP

The last big issue, according to the meeting notes of March, was closed/merged in #159 and already adopted by vendors.

With that said, can we expect a stage 4 presentation in the next meeting (late May)?
That would be an out-of-season Christmas gift!!

[codehag]

I will be proposing it for stage 4 in May.

[codehag]

Spec text integration pr has been posted: tc39/ecma262#2408

[codehag]

Committee waved this through -- we are just waiting on official sign off from the editors.