add file content render

fstree/fs_test.go

@@ -57,9 +57,10 @@ func TestWalkFileSystemAndBuildTree(t *testing.T) {
 				t.Errorf("child %q parent pointer incorrect", child.FileName())
 			}
 
-			if child.nodeType == FileNode {
+			switch child.nodeType {
+			case FileNode:
 				fileCount++
-			} else if child.nodeType == FolderNode {
+			case FolderNode:
 				folderCount++
 				if child.FileName() == "folder1" {
 					folder1 = child

fstree/fstree.go

@@ -11,6 +11,7 @@ import (
 	"errors"
 	"mend/styles"
 	"mend/utils"
+	"os"
 	"path/filepath"
 	"strings"
 
@@ -195,6 +196,22 @@ func (t *FsTree) ToggleSelectedExpand() error {
 	return nil
 }
 
+func (t *FsTree) GetSelectedContent() (string, error) {
+	if t.selected == nil {
+		return "", errors.New("no node is currently selected")
+	}
+
+	if t.selected.nodeType != FileNode {
+		return "", nil
+	}
+
+	contentBytes, err := os.ReadFile(t.selected.path)
+	if err != nil {
+		return "", err
+	}
+	return string(contentBytes), nil
+}
+
 func (t *FsTree) Render() string {
 	builder := &strings.Builder{}
 	t.renderNode(t.root, 0, builder)