unneeded-parens

Flags parentheses written in positions where they don’t change parsing.

Rationale

Parens that don’t affect parsing read as either a typo or copy-paste residue. Removing them clarifies the code without changing behavior.

What triggers

• The right-hand side of an assignment: x = (1 + 2);
• The initializer of a var / const: var x = (1 + 2);
• The value of a return: return (x);
• Parens around a Method(…) type annotation when they aren’t load-bearing, e.g. (Method() as Boolean) as a function return type.

What does not trigger

Positions where parens can affect parsing:

• Operand of a binary operator — 1 * (2 + 3) needs the parens.
• Object position of .member or [index] — (x + 1).foo needs the parens.
• (Method(…) as Return)? — without the parens, the trailing ? binds to Return rather than to the whole callable.

Example

Before:

function f(cb as (Method(x as Number) as Void)?) as (Method() as Boolean) {
    var x = (1 + 2);
    return (method(:g));
}

After --fix:

function f(cb as (Method(x as Number) as Void)?) as Method() as Boolean {
    var x = 1 + 2;
    return method(:g);
}

Fix

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