Quit Neovim when Explorer is the last window

[gbcreation]

Here is a solution to quit Neovim when only Snacks windows remain, based on @marvinth01's solution for nvim-tree.

vim.api.nvim_create_autocmd('QuitPre', {
    callback = function()
        local snacks_windows = {}
        local floating_windows = {}
        local windows = vim.api.nvim_list_wins()
        for _, w in ipairs(windows) do
            local filetype = vim.api.nvim_get_option_value('filetype', { buf = vim.api.nvim_win_get_buf(w) })
            if filetype:match('snacks_') ~= nil then
                table.insert(snacks_windows, w)
            elseif vim.api.nvim_win_get_config(w).relative ~= '' then
                table.insert(floating_windows, w)
            end
        end
        if 1 == #windows - #floating_windows - #snacks_windows then
            -- Should quit, so we close all Snacks windows.
            for _, w in ipairs(snacks_windows) do
                vim.api.nvim_win_close(w, true)
            end
        end
    end,
})