feat: add ternaryOperandBinaryExpressions option to no-extra-parens rule

[kecrily]

Prerequisites checklist

• I have read the contributing guidelines.

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

[x] Documentation update
[ ] Bug fix (template)
[ ] New rule (template)
[x] Changes an existing rule (template)
[ ] Add autofix to a rule
[ ] Add a CLI option
[ ] Add something to the core
[ ] Other, please explain:

What changes did you make? (Give an overview)

a && b ? foo : bar

Such code may not be clear to readers who do not know enough about priorities, whether it is

(a && b) ? foo : bar

or

a && (b ? foo : bar)

To better express the priority, one may choose to add parentheses to it and use no-mixed-operators rule with groups: [['||' , '&&', '?:']] option to check it.

However, no-extra-parens currently reports an error for first case. If there are no parentheses, then no-mixed-operators rule will report another error.

What rule do you want to change?

no-extra-parens

What change do you want to make (place an "X" next to just one item)?

[ ] Generate more warnings
[x] Generate fewer warnings
[ ] Implement autofix
[ ] Implement suggestions

How will the change be implemented (place an "X" next to just one item)?

[x] A new option
[ ] A new default behavior
[ ] Other

Please provide some example code that this change will affect:

(a && b) ? foo : bar

What does the rule currently do for this code?

error  Unnecessary parentheses around expression                              no-extra-parens

What will the rule do after it's changed?

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

[mdjermanovic]

To better express the priority, one may choose to add parentheses to it and use no-mixed-operators rule with groups: [['||' , '&&', '?:']] option to check it.

However, no-extra-parens currently reports an error for first case. If there are no parentheses, then no-mixed-operators rule will report another error.

I agree there should be an option in the no-extra-parens rule to avoid these conflicts with the no-mixed-operators rule, but I think the option should be aligned with the no-mixed-operators rule, i.e., the option should allow those and only those parentheses that no-mixed-operator requires.

As currently implemented in this PR, the new option allows some parentheses that no-mixed-operators doesn't require, for example (foo()) ? bar : baz, and still disallows some parentheses that no-mixed-operators does require, for example foo ? bar : (baz || qux).

[kecrily]

I improved the coverage and both of the ones you mentioned have been resolved. But please let me know if there are other cases that are not covered

[mdjermanovic]

I think the option name should be something like ternaryOperandBinaryExpressions or binaryExpressionsAsTernaryOperands.

[kecrily]

I think the option name should be something like ternaryOperandBinaryExpressions or binaryExpressionsAsTernaryOperands.

My confusion is that the option allows not only BinaryExpressions but also LogicalExpression. But there is only BinaryExpressions in the option name, so will this cause confusion.

[mdjermanovic]

My confusion is that the option allows not only BinaryExpressions but also LogicalExpression. But there is only BinaryExpressions in the option name, so will this cause confusion.

I think it's fine to use "binary" here. It doesn't match ESTree's representation, but logical operators are binary operators, and the existing option nestedBinaryExpressions applies to them too, so I think it's fine to name the new option in a similar way.

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[mdjermanovic]

Marking accepted as this option fixes conflicts with the no-mixed-operators rule.

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[mdjermanovic]

LGTM, thanks!

I'll leave this open until today's release in case anyone else would like to review it.