neovim/plugins/explorer/nvim-tree.lua

-- See: https://github.com/kyazdani42/nvim-tree.lua/blob/master/doc/nvim-tree-lua.txt
require("nvim-tree").setup(@nvimTreeLuaSettings@)

vim.keymap.set("n", "<leader>nt", "<Cmd>NvimTreeToggle<CR>")
vim.keymap.set("n", "<leader>nf", "<Cmd>NvimTreeFindFile<CR>")

local function open_nvim_tree(data)
  -- buffer is a [No Name]
  local no_name = data.file == "" and vim.bo[data.buf].buftype == ""
  -- buffer is a directory
  local directory = vim.fn.isdirectory(data.file) == 1

  if not no_name and not directory then
    return
  end

  -- change to the directory
  if directory then
    vim.cmd.cd(data.file)
  end

  -- open the tree
  require("nvim-tree.api").tree.open()
end

vim.api.nvim_create_autocmd({ "VimEnter" }, { callback = open_nvim_tree })