Cancellable Timeout

Requirements

• Implement cancellableTimeout(callback, delay, ...args). Schedule callback(...args) once after delay milliseconds and return a cancel function.
• Canceling before the deadline prevents the callback from running. The callback must not run immediately.
• Cancellation is idempotent: calling cancel repeatedly or after the timeout fires must be safe.
• Support zero delay, forwarded arguments, and independently cancellable timers. Delay is a non-negative integer.
• Use setTimeout and clearTimeout without modifying the callback.

Examples

Input: const cancel = cancellableTimeout(console.log, 100, "Hello"); cancel();
Output: The pending log is canceled.