Started with the basic version fine, delay the call, cancel if another comes in before wait ms.
Start by clarifying the expected behavior for leading/trailing options and edge cases like immediate invocation and cancellation. Then outline a closure-based implementation using a timer variable and a flag to track the last call time, and finally walk through the code logic for each option combination.
Pro tip: Mention that debounce should return a function with a cancel method to clear pending invocations, and that you'd use Date.now() or performance.now() for precise timing—this shows production awareness beyond the basic implementation.
Ask about the exact semantics of leading/trailing options, whether the function should be called with the latest arguments, and if cancellation or flushing is needed. Confirm that wait is in milliseconds and that the returned function should preserve this context.
Plan to use a closure that maintains a timerId, lastCallTime, and lastArgs. Explain how you'll track whether the debounced function is currently in a 'waiting' state to decide leading/trailing invocations.
Write the debounced function that clears any existing timer, checks if it's the leading edge (first call after wait), and schedules the trailing call. Use setTimeout and clearTimeout to manage the timer.
Add branching for leading, trailing, or both. Implement a cancel method that clears the timer and resets state. Optionally add a flush method to invoke immediately.
Walk through test cases: rapid calls, calls spaced beyond wait, leading-only, trailing-only, and both. Discuss trade-offs like memory usage, timer precision, and whether to use requestAnimationFrame for UI events.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.