shouldn't allow trailing comma after rest parameter in objects

[gsathya]

Input Code

var { ...y, } = { a: 1} 

Babel Configuration (.babelrc, package.json, cli command)

Presets - stage3

Expected Behavior

throws SyntaxError

Current Behavior

No error

Possible Solution

Check for trailing comma and record pattern error.

[babel-bot]

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[xtuc]

I was not able to reproduce this in the Babel's REPL (link).

Coud you please add more detail to the issue?

[gsathya]

I was not able to reproduce this in the Babel's REPL (link).

Coud you please add more detail to the issue?

It's reproducible in your link. There should be a SyntaxError, but there is no error.

[hzoo]

@gsathya yep I had made this change as a patch and it broke react-native so I reverted. It will be a breaking change so we will do it in Babel 7.

Btw in the future if its a syntax error you can report it to babylon instead (the parser) https://github.com/babel/babylon

More context

PR that did this earlier: babel/babylon#149 (comment)
release notes: https://github.com/babel/babylon/releases/tag/v6.11.3

react-native issue: facebook/react-native#10199
rollback release: https://github.com/babel/babylon/releases/tag/v6.11.4

[danez]

This is done in babel/babylon#290