tmux aware nvim pane navigation

tmux_aware_nvim_pane_navigation.vim

" tmux aware navigation
lua << EOF
function pane_switch(direction)
    local vim_hotkeys = { up = "k", down = "j", left = "h", right = "l", }
    local tmux_hotkeys = { up = "U", down = "D", left = "L", right = "R", }
    local before_switch_winnr = vim.fn.winnr()
    vim.api.nvim_feedkeys(
        vim.api.nvim_replace_termcodes("<C-w>"..vim_hotkeys[direction], true, false, true),
        'nx', -- without `x` mode winnr will return same value for before/after
        false
    )
    local after_switch_winnr = vim.fn.winnr()
    -- run tmux command only when needed
    if (before_switch_winnr == after_switch_winnr) and (vim.fn.exists('$TMUX') == 1) then
        local obj = vim.system(
            {'tmux', 'select-pane', '-'..tmux_hotkeys[direction]},
            { text = true }
        ):wait() -- Run synchronously
    end
end

-- create this mappings and function with autocommands
-- :h lua-guide-autocommand-create
-- :h lua-guide-autocommands-group
vim.keymap.set('n', '<C-j>', function() pane_switch('down') end,
               { desc = 'Tmux-aware switch pane to bottom' })
vim.keymap.set('n', '<C-k>', function() pane_switch('up') end,
               { desc = 'Tmux-aware switch pane to up' })
vim.keymap.set('n', '<C-h>', function() pane_switch('left') end,
               { desc = 'Tmux-aware switch pane to left' })
vim.keymap.set('n', '<C-l>', function() pane_switch('right') end,
               { desc = 'Tmux-aware switch pane to right' })
EOF

Created this gist, for several reasons (in order of their priority to me):

1. wanted to simplify my setup and make it more configurable. pane switching is not something you'd like to install with packages. (as a more funny case, I remember javascript package which tells if number is negative
   1. source plugin which I tried to simplify is too robust for this simple task. my 15 lines of code against 140 lines of source code.
2. get experience with lua in vim