Throttle with Leading and Trailing

Throttle with leading/trailing options is the “scroll handler” API: fire immediately, then at most once per window, optionally catching the last call. Naive move Ignore calls inside the window entirely. Users lose the final scroll position update. Where it breaks Leading-off should not fire at the start. Trailing-off should not schedule the tail. Rapid calls must refresh the trailing timer with the latest args. The fix Track lastCallTime, lastArgs, and a timer. If enough time passed and leading is on, invoke now. Else if trailing is on, schedule one timeout for the remaining wait with the newest args. Remember: Trailing exists to keep the last event; leading exists for instant feedback. Say this in the interview: I'd track last invoke time, optionally fire immediately on the leading edge, and schedule a single trailing call with the latest args when calls keep arriving inside the window.