Disallow use of constant expressions in conditions (no-constant-condition)

Comparing a literal expression in a condition is usually a typo or development trigger for a specific behavior.

if (false) {
    doSomethingUnfinished();
}

This pattern is most likely an error and should be avoided.

Rule Details

The rule is aimed at preventing the use of a constant expression in a condition. As such, it warns whenever it sees a constant expression inside a condition expression.

The following patterns are considered warnings:

if (true) {
    doSomething();
}

var result = 0 ? a : b;

while (-2) {
    doSomething();
}

for (;true;) {
    doSomething();
}

do{
    something();
} while (x = -1)

The following patterns are not warnings:

if (x === 0) {
    doSomething();
}

do {
    something();
} while (x)

Version

This rule was introduced in ESLint 0.4.1.

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