Test SelectNodeHandler

src/selectNodeHandler.ts

@@ -64,18 +64,14 @@ export default class SelectNodeHandler {
                 return [];
             }
         } else {
-            const selectedNodes = [];
-
-            for (const id in this.selectedNodes) {
-                if (
-                    Object.prototype.hasOwnProperty.call(this.selectedNodes, id)
-                ) {
-                    const node = this.getNodeById(id);
-                    if (node && parent.isParentOf(node)) {
-                        selectedNodes.push(node);
-                    }
+            const selectedNodes: Node[] = [];
+
+            this.selectedNodes.forEach((id) => {
+                const node = this.getNodeById(id);
+                if (node && parent.isParentOf(node)) {
+                    selectedNodes.push(node);
                 }
-            }
+            });
 
             return selectedNodes;
         }

src/test/selectNodeHandler.test.ts

@@ -0,0 +1,24 @@
+import { Node } from "../node";
+import SelectNodeHandler from "../selectNodeHandler";
+
+describe("getSelectedNodesUnder", () => {
+    it("returns the nodes when the nodes have an id", () => {
+        const node = new Node({ id: 1 });
+
+        const child = new Node({ id: 2 });
+        node.addChild(child);
+
+        const nodeMap = new Map<NodeId, Node>();
+        nodeMap.set(1, node);
+        nodeMap.set(2, child);
+
+        const getNodeById = (id: NodeId) => nodeMap.get(id) ?? null;
+
+        const selectNodeHandler = new SelectNodeHandler({ getNodeById });
+        selectNodeHandler.addToSelection(child);
+
+        expect(
+            selectNodeHandler.getSelectedNodesUnder(node),
+        ).toIncludeAllMembers([child]);
+    });
+});