Change default version to VERSION_ES6

[gbrail]

This changes the version set when a Context object is created to VERSION_ES6 by default.

It also adds language to the JavaDoc to indicate that:

• We will not be adding additional versions after VERSION_ES6, but instead will introduce new features in new versions of Rhino, like other JavaScript engines.
• Code that uses Rhino should plan on migrating to VERSION_ES6.
• Projects that use Rhino should, if possible, stop relying on older language versions, as these typically are features that are incompatible with modern JavaScript.

(Simply changing VERSION_DEFAULT is not sufficient -- VERSION_DEFAULT unfortunately drives a number of odd behaviors that many tests and probably many programs depend on.)

A few other notes:

First, not setting the language level and assuming that Rhino is very very out of date is a common problem with new users -- I hope that this will help in that regard.

Second, a number of tests thought that they were setting the language level but they weren't because they re-used a class that created it's own Context, so that's fixed now!

[p-bakker]

The name 'VERSION_ES6' doesn't really cover what it does anymore, as it basically means: 'the latest version of EcmaScript, as far as Rhino supports it'

Maybe create a new, final language version called VERSION_ECMASCRIPT or just ECMASCRIPT or if not a new language version, then just a new alias for VERSION_ES6?

[gbrail]

Yes -- adding "VERSION_ECMASCRIPT" as an alias, and using that, makes sense to me too. I'll make it an alias, though. Thanks!

…

On Sat, Dec 14, 2024 at 5:21 AM Paul Bakker ***@***.***> wrote: The name 'VERSION_ES6' doesn't really cover what it does anymore, as it basically means: 'the latest version of EcmaScript, as far as Rhino supports it' Maybe create a new, final language version called VERSION_ECMASCRIPT or just ECMASCRIPT or if not a new language version, then just a new alias for VERSION_ES6? — Reply to this email directly, view it on GitHub <#1755 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAD7I25ETHD5AY3V4JSVMB32FQWGXAVCNFSM6AAAAABTRLSOZCVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDKNBTGEYDOOJYHA> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[gbrail]

Check it out -- I switched to VERSION_ECMASCRIPT and kept the old name for compatibility. Thanks for looking at it!

[rbri]

{@link #VERSION_ES6} -> {@link #VERSION_ECMASCRIPT} ?

[rbri]

What about deprecating some of the older versions, including the plan to remove them in some time

[gbrail]

Can we address deprecating some releases in a future issue or PR? Personally I'd like to get rid of pretty much all of that version checking stuff but I have a feeling that will prevent many projects from upgrading to a recent release of Rhino. I'd love to hear how others feel.