fix(ui5-tree): noDataText is now properly rendered (SAP#11095)

There was a problem where noDataText wasn't rendered even if there are no tree items in the tree. This is because there was a an internal element counted as a child of the tree in its tsx template.

With this fix, the noDataText is now properly rendered when there are no tree items in the tree.

Fixes: SAP#11073

Author: plamenivanov91

packages/main/cypress/specs/Tree.cy.tsx

@@ -28,3 +28,21 @@ describe("Tree Tests", () => {
 			.and("have.attr", "accessible-description-ref", "lblDesc2");
 	});
 });
+
+describe("Tree Props", () => {
+	it("noDataText is properly rendered", () => {
+		cy.mount(
+			<>
+				<Tree noDataText="No data"></Tree>
+			</>
+		);
+
+		cy.get("[ui5-tree]")
+			.shadow()
+			.find("[ui5-tree-list]")
+			.shadow()
+			.find("[ui5-busy-indicator]")
+			.find(".ui5-list-nodata")
+			.should("exist")
+	});
+});

packages/main/src/TreeList.ts

@@ -12,7 +12,9 @@ class TreeList extends List {
 		const slottedItems = this.getSlottedNodes<TreeItemBase>("items");
 		const flatItems: Array<TreeItemBase> = [];
 
-		flattenTree(slottedItems, flatItems, includeCollapsed);
+		if (!(slottedItems.length === 1 && slottedItems[0].hasAttribute("ui5-drop-indicator"))) {
+			flattenTree(slottedItems, flatItems, includeCollapsed);
+		}
 
 		return flatItems;
 	}