n><span class="token function">ok</span><span class="token punctuation">(</span>button<span class="token punctuation">.</span>classList<span class="token punctuation">.</span><span class="token function">contains</span><span class="token punctuation">(</span><span class="token string">'is-disabled'</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

  <span class="token comment">// QUnit DOM</span>
  assert<span class="token punctua