No way to enable "no-extra-parens" on JSX and functions only

• ESLint Version: 3.16.1
• Node Version: 6.9.5
• npm Version: 3.10.10

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

Please show your full configuration:

"no-extra-parens": ["error", "all", {
  "conditionalAssign": false,
  "returnAssign": false,
  "nestedBinaryExpressions": false,
  "ignoreJSX": "multi-line"
 }]

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

fn(x, (y ? 25 : 42))

What did you expect to happen?

No error.

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

Gratuitous parentheses around expression. (no-extra-parens)

Backstory:

We were using the no-extra-parens rule with the "functions" option. But we wanted to also enforce that single-line JSX expressions don’t have needless parens. It seemed that changing the rule from:

"no-extra-parens": ["error", "functions"]

To this:

"no-extra-parens": ["error", "all", {
  "conditionalAssign": false,
  "returnAssign": false,
  "nestedBinaryExpressions": false,
  "ignoreJSX": "multi-line"
 }]

Should have done the trick. But apparently "all" includes some checks for extra parens around expressions, but does not offer a way to disable those checks like with the other options (conditionalAssign, returnAssign, nestedBinaryExpressions, etc.)

We only want to prevent single-line JSX and functions from having extra parens, i.e. these two cases:

const z = (<h1>hey</h1>)
((function foo() {}))()

Is it reasonable to allow users to disable these other checks with the second object parameter?

[vitorbal]

If something like a "callExpressionArguments" option is enough to satisfy the use-case for standard, I’d say we can treat this as an enhancement to add just that option.

We can worry about more options in the future, if the need ever comes.

[feross]

@vitorbal Sounds good to me!