Bug Hunt — Auto-Counter Stuck at 1

Debugging — Beginner React challenge.

This counter is supposed to auto-increment by 1 every second while it's running — but it gets stuck at 1 and never climbs any further. This is a debugging challenge: the code already runs, find the stale closure bug and fix it, rather than building the feature from scratch.

Requirements

• While running is true, the count must increase by 1 every 1000ms, indefinitely — not just once.
• Clicking Stop freezes the count at its current, correct value.
• Clicking Start again after a Stop must resume counting upward from wherever it left off, not from 0 and not stuck.
• Start is disabled while running; Stop is disabled while idle.

Signature

function AutoCounter(): JSX.Element

Example

<AutoCounter />
// click "Start Auto", wait 3 seconds
// buggy:   count shows 1 (frozen after the first tick)
// fixed:   count shows 3 (and keeps climbing every second)

Constraints

• Do not remove the useEffect or change its dependency array — the fix is inside the interval callback.
• Do not switch to setTimeout or a ref-based counter — keep using setInterval + setCount.