no-cond-assign

Disallow assignment in conditions

An assignment expression used as a condition tests the assigned value after mutating its target, which can be mistaken for an equality comparison.
Instead, you SHOULD move the assignment before the condition or use a binding condition when the assigned value is intentionally tested.

- Category: suspicious
- Level: warning
- Fix: none
- Scope: module

Reported

function select(next: boolean): boolean {
    let active = false;
    if ((active = next)) {
        return active;
    }
    return false;
}
Accepted

function select(next: boolean): boolean {
    let active = next;
    if (active) {
        return active;
    }
    return false;
}
Prior art

- ESLint · no-cond-assign

language/linter/src/rules/suspicious/nocondassign.rs:7