title: how can know a specific class exist?
body: <p>I am using Vue 3 + vitest</p>
  <p>I am writing a test for component</p>
  <p>and I want to test that if a <strong>completed</strong> props value was <strong>true</strong></p>
  <p>then a <code>div</code> with class <code>done</code> should exist.</p>
  <p>I have a problem with its syntax</p>
  <pre><code>import { describe, it, expect } from 'vitest'
  
  import { mount } from '@vue/test-utils'
  import ToDo from '../ToDo.vue'
  
  describe('test button', () =&gt; {
    it('renders properly', () =&gt; {
      const wrapper = mount(ToDo, { props: { completed: true } })
      expect(wrapper.classes('.done')).toBeDefined()
         
    })
  })
  </code></pre>
  <p>I have written this But it doesn't work correctly and always returns true.</p>
  <p>this is component , I'm going to test it</p>
  <pre><code>&lt;script setup lang=&quot;ts&quot;&gt;
  
  defineProps&lt;{
    completed: boolean
  }&gt;()
  
  &lt;/script&gt;
  
  &lt;template&gt;
    &lt;div class=&quot;row&quot;&gt;
      &lt;button v-if=&quot;completed&quot; class=&quot;done&quot;&gt;done&lt;/button&gt;
  
    &lt;/div&gt;
  &lt;/template&gt;
  </code></pre>
  <p>how can I test this?</p>