Function useActivityQuery

cli/src/hooks/use-activity-query.ts:255–508

(
  options: UseActivityQueryOptions<T>,
)

 * - Can refetch stale data when user becomes active again
 */
export function useActivityQuery<T>(
  options: UseActivityQueryOptions<T>,
): UseActivityQueryResult<T> {
  const {
    queryKey,
    queryFn,
    enabled = true,
    staleTime = 0,
    gcTime = 5 * 60 * 1000,
    retry = 0,
    refetchInterval = false,
    refetchOnMount = false,
    refetchOnActivity = false,
    pauseWhenIdle = false,
    idleThreshold = 30_000,
  } = options

  const serializedKey = serializeQueryKey(queryKey)
  const mountedRef = useRef(true)
  const intervalRef = useRef<ReturnType<typeof setInterval> | null>(null)
  const wasIdleRef = useRef(false)
  
  // Store queryFn in a ref to avoid recreating doFetch when queryFn changes.
  // This is critical because inline arrow functions create new references on every render,
  // which would cause the polling interval to reset constantly.
  const queryFnRef = useRef(queryFn)
  queryFnRef.current = queryFn

  // Snapshot includes entry + isFetching (so fetch-status updates rerender correctly)
  const snap = useSyncExternalStore(
    (cb) => subscribeToKey(serializedKey, cb),
    () => getKeySnapshot<T>(serializedKey),
    () => getKeySnapshot<T>(serializedKey),
  )

  const cachedEntry = snap.entry
  const isFetching = snap.isFetching

  const data = cachedEntry?.data
  const error = cachedEntry?.error ?? null
  const dataUpdatedAt = cachedEntry?.dataUpdatedAt ?? 0

  // Initial load = fetching with no successful data yet
  const isLoading = isFetching && (cachedEntry == null || dataUpdatedAt === 0)

  const doFetch = useCallback(async (): Promise<void> => {
    if (!enabled) return

    // global dedupe
    const existing = inFlight.get(serializedKey)
    if (existing) {
      await existing
      return
    }

    const myGen = getGeneration(serializedKey)
    setQueryFetching(serializedKey, true)