refactor: use zindex for checking if win is float

[willothy]

Relative may soon be delegated to only floats (returning nil for splits), if that's the route I/we decide to take with this PR in core. This PR preemptively addresses that change by checking zindex instead of relative to determine whether a window is floating. This doesn't change any behavior now, so even if that PR isn't merged there will be no side-affects from this, but this ensures we don't break any user configs if/when it is merged.

[cryptomilk]

Can you please add a test? You can probably use screenshot testing for this. Example: https://github.com/echasnovski/mini.nvim/blob/main/tests/test_jump2d.lua#L433

If you set force, then a screenshot will be created, once you have one you can remove it, see: https://github.com/echasnovski/mini.test/blob/main/doc/mini-test.txt#L568

[willothy]

Will do - can't I just check whether the window is floating in the test though? I'm a bit confused on what screenshot would be used to check here

[cryptomilk]

Well, it should not resize the float. So a screenshot will check the float is still intact.

[willothy]

Well, it should not resize the float. So a screenshot will check the float is still intact.

Gotcha, sounds good :)

[willothy]

win_get_width and win_get_height should be enough for this I think, not sure screenshot is needed.

[cryptomilk]

Looks fine for me. Thanks!