use-isnan

Require NaN predicates for equality-based tests

Equality comparisons and Array index searches with NaN have fixed results because NaN is unequal to every value, including itself.
Instead, you MUST call .isNaN() in the direct test or search predicate.

- Category: correctness
- Level: error
- Fix: suggestion
- Scope: module

Reported

function isMissing(value: float64): boolean {
    return value === 0.0 / 0.0;
}
Accepted

function isMissing(value: float64): boolean {
    return value.isNaN();
}
Prior art

- ESLint · use-isnan

language/linter/src/rules/correctness/useisnan.rs:8