How to find out the type of variables?

Question

typescript

Rewriting (range) component from JS to TS.
As I understand, there are two cases, for the desktop and for the mobile version of the

difficulty in determining the type of the parameters of the method.

const handleThumbEnd = (eventData) => thumbHandler(eventData.event, true);
  const handleThumbMove = useThrottledFn(
    (eventData) => thumbHandler(eventData.event),
    250,
  );

  const handlers = useSwipeable({
    onSwiping: handleThumbMove,
    onSwiped: handleThumbEnd,
    preventDefaultTouchmoveEvent: true,
    trackMouse: true,
    trackTouch: true,
  });

eventData specified both MouseEvent and TouchEvent. but I still get an error that eventData.event does not have such a property

Answer 1

something like this:
if (myvar==true ) { }
if (myvar>1) { }
etc.
where it will not give an error, then this type.

Answer 2

Using Beautiful React Hooks and React Swipeable?

Answer 3

If either does not export the types it needs, then I would try this:

type EventData = {
    event: Parameters<typeof thumbHandler>[0];
};

const handleThumbEnd = (eventData: EventData) => thumbHandler(eventData.event, true);
const handleThumbMove = useThrottledFn(
    (eventData: EventData) => thumbHandler(eventData.event),
    250,
);

const handlers = useSwipeable({
    onSwiping: handleThumbMove,
    onSwiped: handleThumbEnd,
    preventDefaultTouchmoveEvent: true,
    trackMouse: true,
    trackTouch: true,
});

or like this:

type HandlerMove = Parameters<typeof useSwipeable>[0]['onSwiping'];
type HandlerEnd = Parameters<typeof useSwipeable>[0]['onSwiped'];

const handleThumbEnd: HandlerMove = (eventData) => thumbHandler(eventData.event, true);
const handleThumbMove: HandlerEnd = useThrottledFn(
    (eventData) => thumbHandler(eventData.event),
    250,
);

const handlers = useSwipeable({
    onSwiping: handleThumbMove,
    onSwiped: handleThumbEnd,
    preventDefaultTouchmoveEvent: true,
    trackMouse: true,
    trackTouch: true,
});

or so