unneeded-parens

Flags (<expr>) written in positions where the parentheses don’t change parsing.

Rationale

A parenthesised expression in certain positions is unambiguous — the grammar accepts any expression there regardless of operator precedence. Wrapping it in extra parens reads as either a typo or copy-paste residue.

What triggers

The rule fires when a (<expr>) appears as:

• the right-hand side of an assignment (x = (1 + 2);),
• the initializer of a var / const binding (var x = (1 + 2);),
• the value of a return statement (return (x);).

In all three slots, removing the parentheses cannot affect operator precedence.

What does not trigger

The rule is intentionally conservative and skips positions where parentheses can matter:

• Operand of a binary operator — 1 * (2 + 3) needs the parens.
• Object position of a .member or [index] — (x + 1).foo needs the parens.
• Anywhere else not in the explicit list above.

Example

Before:

var x = (1 + 2);
function f() {
    return (foo());
}

After --fix:

var x = 1 + 2;
function f() {
    return foo();
}

Fix

The fix replaces the source between the parentheses (trimmed of surrounding whitespace) into the outer span. Comments inside the parens are preserved: (/* tag */ 2 + 3) becomes /* tag */ 2 + 3.