added: smart_split_open function for split windows; so Neovim asks if the user wants to re-open the already open buffer in the current tab as split window or just jump to the existing one

lua/custom/plugins/filetree.lua

@@ -85,6 +85,63 @@ return {
 			end
 		end
 
+		-- Smart_open_split for split windows
+		local function smart_open_split(state, direction)
+			local node = state.tree:get_node()
+			if not node then
+				return
+			end
+			local path = node:get_id()
+
+			if node.type == 'directory' then
+				state.commands.toggle_node(state, node)
+				return
+			end
+
+			-- Check if file is open in another tab
+			local open_tab, open_win
+			for _, tab in ipairs(vim.api.nvim_list_tabpages()) do
+				for _, win in ipairs(vim.api.nvim_tabpage_list_wins(tab)) do
+					local buf = vim.api.nvim_win_get_buf(win)
+					if vim.api.nvim_buf_is_valid(buf) and vim.api.nvim_buf_get_name(buf) == path then
+						open_tab = tab
+						open_win = win
+						break
+					end
+				end
+				if open_tab then
+					break
+				end
+			end
+
+			if open_tab then
+				local choice = vim.fn.confirm('File is already open in another tab. Open split here anyway?', '&Yes\n&No',
+					2)
+				if choice ~= 1 then
+					-- User chose No → jump to the tab where file is open
+					vim.api.nvim_set_current_tabpage(open_tab)
+					vim.api.nvim_set_current_win(open_win)
+					return
+				end
+				-- Else user chose Yes → continue to open split in current tab
+			end
+
+			-- Open split in current tab
+			if direction == 'v' then
+				state.commands.open_vsplit(state)
+				vim.schedule(function()
+					vim.cmd 'wincmd L'
+				end)
+			else
+				state.commands.open_split(state)
+				vim.schedule(function()
+					vim.cmd 'wincmd J'
+				end)
+			end
+
+			vim.cmd('edit ' .. vim.fn.fnameescape(path))
+		end
+
 		require('neo-tree').setup {
 			close_if_last_window = true,
 			popup_border_style = 'rounded',
@@ -101,28 +158,10 @@ return {
 				mappings = {
 					['<cr>'] = smart_open,
 					['v'] = function(state)
-            local node = state.tree:get_node()
-            if node.type == 'directory' then
-              state.commands.toggle_node(state, node)
-              return
-            end
-            local path = node:get_id()
-            state.commands.open_split(state) -- opens horizontal split (top)
-            vim.schedule(function()
-              vim.cmd 'wincmd J'             -- move the new split to bottom
-            end)
+						smart_open_split(state, 'h')
 					end,
 					['h'] = function(state)
-            local node = state.tree:get_node()
-            if node.type == 'directory' then
-              state.commands.toggle_node(state, node)
-              return
-            end
-            local path = node:get_id()
-            state.commands.open_vsplit(state) -- opens vertical split (left)
-            vim.schedule(function()
-              vim.cmd 'wincmd L'              -- move the new split to right
-            end)
+						smart_open_split(state, 'v')
 					end,
 					['t'] = 'noop',
 				},