Is the fix in bug 1421400 Nightly-only?

(In reply to j.j. from comment #3)

Is the fix in bug 1421400 Nightly-only?

Answering myself: Yes, seems so.
This should land in Beta 68 for Chrome compat and for 68 ESR and Fennec.

Chrome 75 ships Numeric Separators in two weeks
https://www.chromestatus.com/feature/5829906369871872

(In reply to j.j. from comment #4)

This should land in Beta 68 for Chrome compat and for 68 ESR and Fennec.

I don't think numeric separators will be used in code shipping to browsers quickly enough that we'd have to worry about Chrome compat here. Even for the ESR I really don't think that this needs to be uplifted.

What would make sense to me is to let it ride the trains either this or the next release—it seems sufficiently low-risk that we don't have to wait very long.

Spec: https://github.com/tc39/proposal-numeric-separator

This was released in V8 release 75 [1], and it sounds like spec concerns have
been figured out and we can let this ride to release.

[1] https://v8.dev/blog/v8-release-75#numeric-separators

Bug 1566516 imported tests from the WASM spec repository that use numeric separators, which caused beta simulation failures in bug 1568806. I can modify the import script to not generate '_' in numeric literals, but it sounds like this is ready to ride the trains to release.

If no one has objections, I'd like to let this ride the trains to release.

https://treeherder.mozilla.org/#/jobs?repo=try&revision=96e7ee047e71d911bb47e7e66c102fb49f287503

I'm unsure if this requires updates to test262-update.py or not. I just removed the NIGHTLY_BUILD's from the initial implementation patch.

https://hg.mozilla.org/mozilla-central/rev/d730bc44f2d7

Doc updates:

• Added to Fx 70 release notes: https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Releases/70#JavaScript
• Added to numeric literal reference docs: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Lexical_grammar#Numeric_separators
• Added an example to parseInt that it won't work with numeric separators: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/parseInt#Examples

fwiw, I think the error messages in Chrome are better.

• We mostly throw: "SyntaxError: missing digit after '_' numeric separator"
• Chrome throws:
  • "Numeric separators are not allowed at the end of numeric literals" for 1_
  • "Only one underscore is allowed as numeric separator" for 1__1
• Separator after null is fine, though
  • Firefox: "numeric separators '_' are not allowed in numbers that start with '0'"
  • Chrome: "Numeric separator can not be used after leading 0."

:till, can you review if the docs look alright?
Also, do you think we should make our error messages better?

The docs look great! The only small nit is that "Only one underscore is allowed" is slightly ambiguous, but I don't think that's a problem in practice, as the example right below makes clear what it means.

Making the error messages better would be good, yes. Could you file a new bug for that?

Florian; see Till's comments above.

Thanks for your feedback, Till!
Reworded to remove ambiguity and filed https://bugzilla.mozilla.org/show_bug.cgi?id=1589072 for potentially improving the error messages.