fix(tree): custom icons cannot be clicked without child nodes (#4638)

* fix(tree): custom icons cannot be clicked without child nodes

close #4571

* test: add test example

src/tree/__tests__/expand.test.jsx

@@ -2,6 +2,9 @@ import { mount } from '@vue/test-utils';
 import Tree from '@/src/tree/index.ts';
 import { delay } from './kit';
 import { ref } from './adapt';
+import { Icon } from 'tdesign-icons-vue-next';
+import { nextTick } from 'vue';
+import { get } from 'lodash';
 
 describe('Tree:expand', () => {
   vi.useRealTimers();
@@ -376,6 +379,37 @@ describe('Tree:expand', () => {
       expect(wrapper.find('[data-value="t1.1"]').exists()).toBe(true);
     });
 
+    it('自定义图标-点击父节点图标可触发展开子节点', async () => {
+      const data = [
+        {
+          value: 't1',
+          children: [
+            {
+              value: 't1.1',
+            },
+          ],
+        },
+      ];
+      const wrapper = mount({
+        render() {
+          return <Tree transition={false} data={data} icon={() => <Icon name="folder" />}></Tree>;
+        },
+      });
+      //  测试: 点击一级 一级展开 二级存在
+      wrapper.find('[data-value="t1"] .t-tree__icon').trigger('click');
+      await delay(10);
+      const t1d1 = wrapper.find('[data-value="t1.1"]');
+      expect(t1d1.attributes('class')).toContain('t-tree__item--visible');
+      const t1 = wrapper.find('[data-value="t1"]');
+      expect(t1.attributes('class')).toContain('t-tree__item--open');
+
+      //  测试:点击二级 二级状态不展开
+      wrapper.find('[data-value="t1.1"] .t-tree__icon').trigger('click');
+      await delay(10);
+      const t1d1_two = wrapper.find('[data-value="t1.1"]');
+      expect(t1d1_two.attributes('class')).not.toContain('t-tree__item--open');
+    });
+
     it('点击已展开的父节点图标，可触发收起子节点', async () => {
       const data = [
         {

src/tree/hooks/useTreeAction.ts

@@ -47,6 +47,9 @@ export default function useTreeAction(state: TypeTreeState) {
 
   const toggleExpanded = (item: TypeTargetNode): TreeNodeValue[] => {
     const node = getNode(store, item);
+
+    if (!node.children) return;
+
     return setExpanded(node, !node.isExpanded());
   };