Release 4.0

[ariya]

• Bump version number
• Update ChangeLog
• Update devDependencies
• Check for performance regression
• Tag the repository
• Publish to npm
• Build the doc on readthedocs
• Announce in the mailing-list
• Update web site

What goes into this release? New ES2017 syntax support:

• ES2017: Trailing commas in function parameter lists and calls #1550 Trailing commas in function parameter lists and calls
• ES2017: Async Function and await expression #1079 Async Function and await expression

API change:

• Explicitly distinguish parsing a module vs a script #1577 Emphasize parseScript vs parseModule

Other relevant improvements:

• Use Read the Docs for the documentation #1477 Host extensive documentation at https://esprima.readthedocs.io
• Use TypeScript 2.0 #1572 Use TypeScript 2.0
• Refactoring and clean-up #1720 Refactoring and clean-up
• Run browser tests with Microsoft Edge #1727 Run browser tests with Microsoft Edge
• Run CI with Node.js v8 #1836 Run CI with Node.js v8

And tons of various fixes!

• Numeric literals in JSX fail to parse #1786 Fix JSX non-empty container
• Allow JSX Element in a yield expression #1765 Allow JSX element in a yield expression
• incorrectly disallows in expressions in function-bodied arrows in for statement initialisers #1793 Allow in expression in a concise body with a function body
• Setter function argument must not be a rest parameter #1693 Setter function argument must not be a rest parameter
• [ES2016] Only functions with simple parameter list can have strict mode directive #1677 Limit strict mode directive to functions with a simple parameter list
• No exception for keywords with escaped characters #1612 Prohibit any escape sequence in a reserved word
• Incorrectly accepts \x{0} in string/template literals #1619 Only permit hex digits in hex escape sequence
• Incorrectly accepts invalid LabeledStatement (ES2015) #1484 Prohibit labelled class/generator/function declaration
• Function declaration as if statement clause should be prohibited in strict mode #1657 Limit function declaration as if statement clause only in non-strict mode
• Extend missing ) tolerate support to with and do-while #1481 Tolerate missing ) in a with and do-while statement

[ariya]

Looks like we need to keep only trailing commas and async/await for 4.0.

From the most recent TC-39 meeting on Jan 24-26, the above two are the only syntax changes which made it to the expected 2017 spec.

Any other opinions and perspectives (perhaps from the Foundation representatives on TC-39) will be appreciated.

[hzoo]

Yeah the other 2 are stage-3 are still I believe

[ariya]

Also useful: http://www.2ality.com/2016/02/ecmascript-2017.html.

[ariya]

Non-ES2017 syntax features are bumped to major version update 5.0 (#1743).

[samgurtman-zz]

Question: What is the release time line for this, for those of us already using ES2017 feature?

[ariya]

@samgurtman Keep an eye on the projects page: https://github.com/jquery/esprima/projects.

[samgurtman-zz]

Thanks!

…

On 29/03/2017 12:51 AM, "Ariya Hidayat" ***@***.***> wrote: @samgurtman <https://github.com/samgurtman> Keep an eye on the projects page: https://github.com/jquery/esprima/projects. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#1589 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AGIKX5q31hwOgM6xOD2fZdFHut_5RTWoks5rqPQ6gaJpZM4KSoQb> .

[joseandrespg]

Hi!

Do we have an estimate release date for this version? The previous one was due in April.

We would love to use this new ES2017 support! Thanks!

[ariya]

No noticeable performance difference is observed.

Version 3.1.3:

    Underscore 1.5.2    42.5 KiB      4.94 ms ± 0.88%
      Backbone 1.1.0    58.7 KiB      5.08 ms ± 3.34%
      MooTools 1.4.5   156.7 KiB     23.05 ms ± 0.59%
        jQuery 1.9.1   262.1 KiB     25.30 ms ± 1.06%
          YUI 3.12.0   330.4 KiB     23.31 ms ± 0.41%
 jQuery.Mobile 1.4.2   442.2 KiB    102.11 ms ± 5.33%
       Angular 1.2.5   701.7 KiB     71.23 ms ± 5.10%
                     ------------------------
                      1994.3 KiB    255.02 ms ± 4.36%

Version 4.0.0:

    Underscore 1.5.2    42.5 KiB      4.85 ms ± 0.71%
      Backbone 1.1.0    58.7 KiB      4.72 ms ± 0.64%
      MooTools 1.4.5   156.7 KiB     22.43 ms ± 0.49%
        jQuery 1.9.1   262.1 KiB     32.00 ms ± 7.82%
          YUI 3.12.0   330.4 KiB     23.32 ms ± 0.40%
 jQuery.Mobile 1.4.2   442.2 KiB     93.42 ms ± 4.32%
       Angular 1.2.5   701.7 KiB     73.53 ms ± 4.37%
                     ------------------------
                      1994.3 KiB    254.26 ms ± 4.49%

(Tested with Node.js 8.0, using V8 5.8)

[ariya]

The npm package has been published and the web site has been updated. Enjoy the release!