bool-comparison

Flags == / != comparisons against a boolean literal, which can be written as the operand itself or its negation.

Rationale

Comparing a boolean expression to true or false restates what the expression already says. if (ready == true) reads as “if ready is true”, which is just “if ready”; if (ready == false) is “if not ready”. Dropping the literal removes the redundant comparison and leaves the condition saying exactly what it means.

What triggers

An == or != binary expression where exactly one side is the literal true or false. The literal may be on either side, so true == ready is treated the same as ready == true.

What does not trigger

• Both sides literal — true == false is a constant with no clearer form.
• Any operator other than == / !=; count > 0 is left alone.
• Expressions that don’t compare against a boolean literal at all.

Example

Before:

function f() {
    if (ready == true) {
        start();
    }

    return done != false;
}

After --fix:

function f() {
    if (ready) {
        start();
    }

    return done;
}

Fix

The fix replaces the whole comparison with the surviving operand, copied verbatim from the source. When the rewrite negates an operand that is itself a binary or ternary expression, it is wrapped in parentheses so ! still binds the whole expression — a < b == false becomes !(a < b), not !a < b.