src/util.ts

export function delay<T>(ms: number, then: () => Promise<T>) {
    let interval: NodeJS.Timeout | undefined;
    const promise = new Promise(resolve => interval = setTimeout(resolve, ms)).then(then);
    return {
        cancel() { clearTimeout(interval); },
        promise
    };
}

export function notEmpty<TValue>(value: TValue | null | undefined): value is TValue {
    return value !== null && value !== undefined;
}

export function numberOrZero(s: string | null | undefined): number {
    const num = Number(s);
    return num > 0 ? num : 0
}