test(Tab): add dynamic insert case (#6102)

src/tab/test/insert.spec.js

@@ -0,0 +1,27 @@
+import { mount, later } from '../../../test';
+
+// this case will throw wierd error in index.spec.js
+// so separate it
+test('insert tab dynamically', async () => {
+  const wrapper = mount({
+    template: `
+      <van-tabs v-model="active">
+        <van-tab title="1">1</van-tab>
+        <div v-if="insert">
+          <van-tab title="2">2</van-tab>
+        </div>
+        <van-tab title="3">3</van-tab>
+      </van-tabs>
+    `,
+    data() {
+      return {
+        insert: false,
+        active: 1,
+      };
+    },
+  });
+
+  await later();
+  wrapper.setData({ insert: true });
+  expect(wrapper).toMatchSnapshot();
+});