Function useEvent

src/client/hooks/useEvent.ts:12–35

(fn: T)

) => ReturnType<T>;

export function useEvent<T extends Noop>(fn: T) {
  if (process.env.NODE_ENV === 'development') {
    if (typeof fn !== 'function') {
      console.error(
        `useMemoizedFn expected parameter is a function, got ${typeof fn}`
      );
    }
  }

  const fnRef = useRef<T>(fn);

  // why not write `fnRef.current = fn`?
  // https://github.com/alibaba/hooks/issues/728
  fnRef.current = useMemo(() => fn, [fn]);

  const memoizedFn = useRef<PickFunction<T>>();
  if (!memoizedFn.current) {
    memoizedFn.current = function (this, ...args) {
      return fnRef.current.apply(this, args);
    };
  }

  return memoizedFn.current as T;
}

/**
 * Same with useEvent but return loading state