title: Argument of type '() => () => Promise<void>' is not assignable to parameter of type 'EffectCallback'
body: <p>My code is:</p>
  <pre><code>    useEffect(() =&gt; {
          document.querySelector('body').style['background-color'] = 'rgba(173, 232, 244,0.2)';
          window.$crisp.push(['do', 'chat:hide']);
  
          return async () =&gt; {
              window.$crisp.push(['do', 'chat:show']);
              document.querySelector('body').style['background-color'] = '#ffffff';
              if (router.query.id) {
                  const resDoc = await firebase.firestore().doc(`documents/${router.query.id}`).get();
                  if (resDoc.exists) {
                      await clearDocPrediction(router.query.id);
                  }
              }
          };
      }, []);
  </code></pre>
  <p>Now the reason I'm returning is because I believe that it performs function cleanup on unload, so I need to keep that. This is some sort of build error that I'm not quite sure how to resolve. Any help would be greatly appreciated.</p>