Fix: no-extra-parens export default sequence expression false positive

[mdjermanovic]

Prerequisites checklist

• I have read the contributing guidelines.
• The team has reached consensus on the changes proposed in this pull request. If not, I understand that the evaluation process will begin with this pull request and won't be merged until the team has reached consensus.

What is the purpose of this pull request? (put an "X" next to an item)

[X] Bug fix

Tell us about your environment

• ESLint Version: v7.0.0-alpha.2
• Node Version: v12.14.0
• npm Version: v6.13.4

What parser (default, Babel-ESLint, etc.) are you using?

default

Please show your full configuration:

Configuration

module.exports = {
    parserOptions: {
        ecmaVersion: 2015,
        sourceType: "module"
    }
};

What did you do? Please include the actual source code causing the issue.

Online Demo Link (v6.8.0)

/* eslint no-extra-parens: "error"*/

export default (a, b);

What did you expect to happen?

No errors.

ExportDeclaration allows only HoistableDeclaration, ClassDeclaration or AssignmentExpression after export default.

a, b is neither of them, it's Expression.

What actually happened? Please include the actual, raw output from ESLint.

Autofix to:

/* eslint no-extra-parens: "error"*/

export default a, b;

Parsing error on the fixed code:

  3:17  error  Parsing error: Unexpected token ,

What changes did you make? (Give an overview)

Added precedence check for ExportDefaultDeclaration's declaration node.

Is there anything you'd like reviewers to focus on?

[yeonjuan]

LGTM! Thanks!

[kaicataldo]

LGTM, thanks!