Updated Neo-tree opening files in a new tab by pressing Enter but replacing an empty buffer by opening in the same tab, Added <leader>e to open an empty buffer in a new tab, fixed Neo-tree starting on left side if Neovim is opened inside a directory

lua/custom/plugins/filetree.lua

@@ -10,13 +10,77 @@ return {
     "MunifTanjim/nui.nvim",
   },
   config = function()
+  
+  -- smart_open function: If there's an empty "No Name" buffer, replace it and open files in the same tab
+local function smart_open(state)
+	local node = state.tree:get_node()
+	if not node then return end
+	local path = node:get_id()
+
+	-- Get the window in the current tab that is NOT Neo-tree
+	local wins = vim.api.nvim_tabpage_list_wins(0)
+	local target_buf = nil
+	for _, win in ipairs(wins) do
+		local buf = vim.api.nvim_win_get_buf(win)
+		local bufname = vim.api.nvim_buf_get_name(buf)
+		local buftype = vim.api.nvim_buf_get_option(buf, "buftype")
+		local modified = vim.api.nvim_buf_get_option(buf, "modified")
+		-- find a window with empty, unmodified buffer
+		if bufname == "" and buftype == "" and not modified then
+			   target_buf = buf
+			   vim.api.nvim_set_current_win(win)
+			   break
+		end
+	end
+
+	if target_buf then
+		-- replace the empty buffer
+		vim.cmd("edit " .. path)
+	else
+		-- otherwise open in new tab
+		require("neo-tree.sources.filesystem.commands").open_tabnew(state)
+	end
+end
+
     require('neo-tree').setup {
-      filesystem = {
-        filtered_items = {
+    -- Open Neo-tree in a floating window in middle at first launch when Neovim is opened inside a directory with "nvim ."
+    	close_if_last_window = true, -- close Neo-tree if it's the last window
+  	popup_border_style = "rounded",
+	enable_git_status = true,
+	enable_diagnostics = true,
+	default_component_configs = {
+	  indent = {
+	    padding = 1,
+	    indent_size = 2,
+	  },
+    	  icon = {
+		folder_closed = "",
+	        folder_open = "",
+	        folder_empty = "ﰊ",
+    	  },
+  	},
+    	window = {
+    	  position = "float",  -- this makes Neo-tree open in the middle
+          width = 40,
+          mapping_options = {
+           noremap = true,
+           nowait = true,
+          },
+	  mappings = {
+	   ["<cr>"] = smart_open, -- Enter → always open file in new tab if there's no empty buffer
+	   ["t"]    = "noop",        -- disable t
+	  },
+	},
+        filesystem = {
+	  follow_current_file = true,
+	  use_libuv_file_watcher = true,
+	  hijack_netrw_behavior = "open_default",
+          filtered_items = {
           visible = true, -- This is what you want: If you set this to `true`, all "hide" just mean "dimmed out"
           hide_dotfiles = false,
           hide_gitignored = true,
-        },
-      }, }
+          },
+        }, 
+      }
   end,
 }