Address issue #219

Ensure better checks for nil / empty pointers when using reflection.

Author: daveshanley

builder/graph.go

@@ -264,7 +264,7 @@ func disableNode(node *model.NodeData[any]) {
 func DigIntoObject[T any](parent *model.NodeData[any], field reflect.Value, nodes *[]*model.NodeData[any],
 	label string, edges *[]*model.EdgeData[any]) {
 
-	if !field.IsZero() {
+	if !field.IsZero() && field.Elem().IsValid() && !field.Elem().IsZero() {
 		lowerLabel := strings.ToLower(label)
 		n := buildNode(lowerLabel, calcWidth(lowerLabel), DefaultHeight, nil)
 		if parent != nil {
@@ -289,20 +289,22 @@ func BuildSliceGraphNode[T any](parent *model.NodeData[any], field reflect.Value
 	if !field.IsZero() {
 		for k := 0; k < field.Len(); k++ {
 			f := field.Index(k)
-			lowerLabel := strings.ToLower(label)
-			n := buildNode(lowerLabel, calcWidth(lowerLabel), DefaultHeight, nil)
-			if parent != nil {
-				e := &model.EdgeData[any]{
-					Id:   fmt.Sprintf("%s-to-%s", parent.Id, n.Id),
-					From: parent.Id,
-					To:   n.Id,
+			if f.Elem().IsValid() && !f.Elem().IsZero() {
+				lowerLabel := strings.ToLower(label)
+				n := buildNode(lowerLabel, calcWidth(lowerLabel), DefaultHeight, nil)
+				if parent != nil {
+					e := &model.EdgeData[any]{
+						Id:   fmt.Sprintf("%s-to-%s", parent.Id, n.Id),
+						From: parent.Id,
+						To:   n.Id,
+					}
+					*edges = append(*edges, e)
 				}
-				*edges = append(*edges, e)
+				disableNode(n)
+				*nodes = append(*nodes, n)
+				obj := f.Elem().Interface().(T)
+				exploreGraphObject(n, &obj, nodes, edges)
 			}
-			disableNode(n)
-			*nodes = append(*nodes, n)
-			obj := f.Elem().Interface().(T)
-			exploreGraphObject(n, &obj, nodes, edges)
 		}
 	}
 }

builder/tree.go

@@ -287,7 +287,7 @@ func extractChangeCount(change reports.HasChanges) (int, int) {
 }
 
 func DigIntoTreeNode[T any](parent *model.TreeNode, field reflect.Value, label string, tc, br int) {
-	if !field.IsZero() {
+	if !field.IsZero() && field.Elem().IsValid() && !field.Elem().IsZero() {
 		e := &model.TreeNode{
 			TitleString:     label,
 			Key:             uuid.New().String(),
@@ -320,23 +320,25 @@ func DigIntoTreeNodeSlice[T any](parent *model.TreeNode, field reflect.Value, la
 	if !field.IsZero() {
 		for k := 0; k < field.Len(); k++ {
 			f := field.Index(k)
-			e := &model.TreeNode{
-				TitleString: transformLabel(label),
-				Key:         uuid.New().String(),
-				IsLeaf:      false,
-				Selectable:  false,
-				Disabled:    false,
-			}
-			obj := f.Elem().Interface().(T)
-			ch, br := countChanges(obj)
-			if ch > -1 {
-				e.TotalChanges = ch
-			}
-			if br > -1 {
-				e.BreakingChanges = br
+			if f.Elem().IsValid() && !f.Elem().IsZero() {
+				e := &model.TreeNode{
+					TitleString: transformLabel(label),
+					Key:         uuid.New().String(),
+					IsLeaf:      false,
+					Selectable:  false,
+					Disabled:    false,
+				}
+				obj := f.Elem().Interface().(T)
+				ch, br := countChanges(obj)
+				if ch > -1 {
+					e.TotalChanges = ch
+				}
+				if br > -1 {
+					e.BreakingChanges = br
+				}
+				parent.Children = append(parent.Children, e)
+				exploreTreeObject(e, &obj)
 			}
-			parent.Children = append(parent.Children, e)
-			exploreTreeObject(e, &obj)
 		}
 	}
 }

cmd/tree.go

@@ -225,15 +225,17 @@ func BuildSliceTreeNode[T any](list *[]pterm.LeveledListItem, field reflect.Valu
 	if !field.IsZero() {
 		for k := 0; k < field.Len(); k++ {
 			f := field.Index(k)
-			ob := f.Elem().Interface().(T)
-			*list = append(*list, pterm.LeveledListItem{Level: level, Text: label})
-			buildConsoleTreeNode(list, &ob, level+1, markdown)
+			if f.Elem().IsValid() && !f.Elem().IsZero() {
+				ob := f.Elem().Interface().(T)
+				*list = append(*list, pterm.LeveledListItem{Level: level, Text: label})
+				buildConsoleTreeNode(list, &ob, level+1, markdown)
+			}
 		}
 	}
 }
 
 func DigIntoObject[T any](list *[]pterm.LeveledListItem, field reflect.Value, level int, label string, markdown bool) {
-	if !field.IsZero() {
+	if !field.IsZero() && field.Elem().IsValid() && !field.Elem().IsZero() {
 		*list = append(*list, pterm.LeveledListItem{Level: level, Text: label})
 		level++
 		obj := field.Elem().Interface().(T)

tui/build_tree.go

@@ -279,8 +279,10 @@ func BuildSliceTreeNode[T any](field reflect.Value, root *tview.TreeNode, obj an
 		root.AddChild(node)
 		for k := 0; k < field.Len(); k++ {
 			f := field.Index(k)
-			ob := f.Elem().Interface().(T)
-			buildTreeNode(node, &ob)
+			if f.Elem().IsValid() && !f.Elem().IsZero() {
+				ob := f.Elem().Interface().(T)
+				buildTreeNode(node, &ob)
+			}
 		}
 	}
 }
@@ -310,7 +312,7 @@ func CreateNode(name string, object any) *tview.TreeNode {
 }
 
 func DigIntoObject[T any](root, node *tview.TreeNode, field reflect.Value) {
-	if !field.IsZero() {
+	if !field.IsZero() && field.Elem().IsValid() && !field.Elem().IsZero() {
 		obj := field.Elem().Interface().(T)
 		buildTreeNode(node, &obj)
 		root.AddChild(node)