error opening file when window.width is not lua number and neo-tree is only opened window

[williamhCode]

When I set window.width to a string or a function, neo-tree throws an error when trying to open a file when neo-tree is the only window open.

It works fine when I have neo-tree open and another window open, only when neo-tree is the only buffer open, it breaks.

Example setup:

require("neo-tree").setup({
  window = {
    width = "30%"
  }
})

Error code:

E5108: Error executing lua: ...cal/share/nvim/lazy/neo-tree.nvim/lua/neo-tree/utils.lua:508: Expected lua number
stack traceback:
        [C]: in function 'nvim_win_set_width'
        ...cal/share/nvim/lazy/neo-tree.nvim/lua/neo-tree/utils.lua:508: in function 'open_file'
        ...y/neo-tree.nvim/lua/neo-tree/sources/common/commands.lua:561: in function 'open'
        ...y/neo-tree.nvim/lua/neo-tree/sources/common/commands.lua:592: in function 'open_with_cmd'
        ...y/neo-tree.nvim/lua/neo-tree/sources/common/commands.lua:601: in function 'open'
        ...o-tree.nvim/lua/neo-tree/sources/filesystem/commands.lua:184: in function 'func'
        ...are/nvim/lazy/neo-tree.nvim/lua/neo-tree/ui/renderer.lua:782: in function <...are/nvim/lazy/neo-tree.nvim/lua/neo-tree/ui/renderer.lua:780>

From my understanding of the code, I'm guessing it works normally because neo-tree uses nui to open the split, and nui accepts percentages and functions. However, when opening a file when neo-tree is the only window, vim.api.nvim_win_set_width is called and window.width is passed without any extra processing.

Perhaps the code similar to calc_container_width could be used, as container width support strings and functions already.

[williamhCode]

I made a quick fix here, lmk if I should make a PR.

[cseickel]

I made a quick fix here, lmk if I should make a PR.

Yes please!