setWaitingInterval.ts

setWaitingInterval.ts

const map = new Map<number, number>();

let waitingIntervalId = 0;

function getLastUntilOneLeft(arr: number[]): number {
    if (arr.length > 1) {
        const item = arr.pop();

        if(typeof item !== 'number'){
            throw new Error('Invalid item type');
        }

        return item;
    }

    return arr[0];
}

/**
 * This function mimics the behavior of setInterval with one key difference:
 * if the callback function takes too long to execute or if the browser throttles,
 * subsequent calls to the callback function will not occur.
 *
 * Additionally, we pass an array of timeouts to define an increasing delay period.
 * For example, given the array [16, 8, 4, 2], the delays will be 2, 4, 8, 16, 16, 16...
 */
export function setWaitingInterval(handler: Function, timeouts: number[], ...args: any[]): number {
    waitingIntervalId += 1;

    function internalHandler(...argsInternal: any[]): void {
        handler(argsInternal);
        map.set(
            waitingIntervalId,
            window.setTimeout(internalHandler, getLastUntilOneLeft(timeouts), ...args)
        );
    }

    map.set(
        waitingIntervalId,
        window.setTimeout(internalHandler, getLastUntilOneLeft(timeouts), ...args)
    );

    return waitingIntervalId;
}

export function clearWaitingInterval(intervalId: number): void {
    const realTimeoutId = map.get(intervalId);

    if (typeof realTimeoutId === 'number') {
        clearTimeout(realTimeoutId);
    }
}