title: Async jest function not receiving 100% branch coverage
body: <p>I have this function:</p>
  
  <pre><code>async testTheTest () {
    return 'tested'
  }  
  </code></pre>
  
  <p>And this test:</p>
  
  <pre><code>it('test this', async () =&gt; {
    await expect(wrapper.vm.testTheTest()).resolves.toBe('tested')
  })
  </code></pre>
  
  <p>When I run this test my code coverage is 100%, but my branch coverage isn't. I think that this has to do with the return value supposedly not being tested, but am unsure why. If I change the function to be:</p>
  
  <pre><code>testTheTest () {
    return 'tested'
  }  
  </code></pre>
  
  <p>The branch coverage suddenly is 100%. It isn't an issue for this specific function since it doesn't contain any async code, but the issue appears in other functions as well.</p>
  
  <p>Languages used: Vue, Jest and Istanbul
  Jest is updated to the latest version, but the issue seems to appear in older versions as well.</p>