Removes default impl to allow for existence tests

src/views/nodes/viewNode.ts

@@ -121,9 +121,7 @@ export abstract class ViewNode {
 
 	abstract getTreeItem(): TreeItem | Promise<TreeItem>;
 
-	resolveTreeItem(item: TreeItem): TreeItem | Promise<TreeItem> {
-		return item;
-	}
+	resolveTreeItem?(item: TreeItem): TreeItem | Promise<TreeItem>;
 
 	getCommand(): Command | undefined {
 		return undefined;

src/views/viewBase.ts

@@ -277,7 +277,7 @@ export abstract class ViewBase<
 	}
 
 	resolveTreeItem(item: TreeItem, node: ViewNode): TreeItem | Promise<TreeItem> {
-		return node.resolveTreeItem(item);
+		return node.resolveTreeItem?.(item) ?? item;
 	}
 
 	protected onElementCollapsed(e: TreeViewExpansionEvent<ViewNode>) {