delay-function.ts

/**
 * This function is a placeholder to simulate an AJAX call to the server.
 *
 * It is able to wait for the specified amount of time, with an option to randomly fail for simulation purposes.
 *
 * @param timeout - The time in milliseconds to wait before returning control.
 * @param probability - The percentage likelihood of this function returning the expected outcome. Value has to be between 0 and 1, otherwise, the value is ignored. The higher the value, the more likely it is to happen. Optional. If not specified, this function will always resolve.
 * @param result - The return payload for a success simulation. Optional.
 */
export async function delay<T>(
  timeout: number,
  probability?: number,
  result?: T
): Promise<T> {
  return new Promise<T>((resolve, reject) => {
    setTimeout(() => {
      if (!probability || probability < 0 || probability > 1) {
        resolve(result);
        return;
      }

      const hit = Math.random();
      if (hit < probability) {
        resolve(result);
      } else {
        reject(
          `Placeholder rejection (${Math.round(
            hit * 100
          )}%) - this should NOT appear in production`
        );
      }
    }, timeout);
  });
}