Lua function to close hidden buffers in Neovim on buffer switch

close_hidden_buffers.lua

-- Define the close_hidden_buffers function
local function close_hidden_buffers()
  local curr_buf_num = vim.api.nvim_get_current_buf()
  local all_buf_nums = vim.api.nvim_list_bufs()

  for _, buf_num in ipairs(all_buf_nums) do
    if buf_num ~= curr_buf_num and vim.api.nvim_buf_is_valid(buf_num) and vim.api.nvim_buf_is_loaded(buf_num) and vim.fn.bufwinnr(buf_num) == -1 then
      if vim.fn.getbufvar(buf_num, '&buftype') ~= 'terminal' then
        vim.api.nvim_buf_delete(buf_num, { force = true })
      end
    end
  end
end

-- Set up the autocommand to run the function when switching buffers
vim.api.nvim_create_autocmd('BufLeave', {
  callback = close_hidden_buffers
})