fix(examples): draw nested structure in file tree example

examples/tree/files/main.go

@@ -4,25 +4,69 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"strings"
 
 	"github.com/charmbracelet/lipgloss"
 	"github.com/charmbracelet/lipgloss/tree"
 )
 
+func addBranches(root *tree.Tree, path string) error {
+	items, err := os.ReadDir(path)
+	if err != nil {
+		return err
+	}
+
+	for _, item := range items {
+		if item.IsDir() {
+			// It's a directory.
+
+			// Skip directories that start with a dot.
+			if strings.HasPrefix(item.Name(), ".") {
+				continue
+			}
+
+			treeBranch := tree.Root(item.Name())
+			root.Child(treeBranch)
+
+			// Recurse.
+			branchPath := filepath.Join(path, item.Name())
+			if err := addBranches(treeBranch, branchPath); err != nil {
+				return err
+			}
+		} else {
+			// It's a file.
+
+			// Skip files that start with a dot.
+			if strings.HasPrefix(item.Name(), ".") {
+				continue
+			}
+
+			root.Child(item.Name())
+		}
+	}
+
+	return nil
+}
+
 func main() {
 	enumeratorStyle := lipgloss.NewStyle().Foreground(lipgloss.Color("240")).PaddingRight(1)
 	itemStyle := lipgloss.NewStyle().Foreground(lipgloss.Color("99")).Bold(true).PaddingRight(1)
 
-	t := tree.Root(".").EnumeratorStyle(enumeratorStyle).ItemStyle(itemStyle)
-	_ = filepath.Walk(".", func(path string, info os.FileInfo, err error) error {
-		if err != nil {
-			return err
-		}
-		if info.IsDir() {
-			t.Child(tree.Root(path))
-		}
-		return nil
-	})
+	pwd, err := os.Getwd()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error getting current working directory: %v\n", err)
+		os.Exit(1)
+	}
+
+	t := tree.Root(pwd).
+		EnumeratorStyle(enumeratorStyle).
+		RootStyle(itemStyle).
+		ItemStyle(itemStyle)
+
+	if err := addBranches(t, "."); err != nil {
+		fmt.Fprintf(os.Stderr, "Error building tree: %v\n", err)
+		os.Exit(1)
+	}
 
 	fmt.Println(t)
 }