Fix top & left calculation

[janosorcsik]

[wmertens]

Fixes #12

Would this not be better as

        top: "top" in rect ? rect.top : rect.y,
        left: "left" in rect ? rect.left : rect.x,

[janosorcsik]

In older browsers, the getBoundingClientRect function doesn't return with the x and y. Every browser fills the top and left properties so the first part of your condition is always true.

[wmertens]

So if top and left always exist, why polyfill them?

[wmertens]

in fact, maybe the function should check if any props are missing, and otherwise return the object unchanged.

[janosorcsik]

I fixed. Thank you @wmertens 👍

[daneroo]

I found this as well. Actually both top and left are inverted.

  const [ref, { x: left, y: top}] = useDimensions()

[janosorcsik]

@Swizec can you check this PR, please?