swc/crates/swc_ecma_parser/tests/tsc/controlFlowIteration.ts

// @strictNullChecks: true

let cond: boolean;

function ff() {
    let x: string | undefined;
    while (true) {
        if (cond) {
            x = "";
        }
        else {
            if (x) {
                x.length;
            }
            if (x) {
                x.length;
            }
        }
    }
}