title: Returning promise from async function
body: <p>Can promise to be returned like below? Does the catch block return a promise or a normal Error?</p>
  <pre><code>async function beforeProcessing(ctx) {
    try {
        let res = await validateList(ctx)
        return new Promise((resolve, reject) =&gt; {
            if (res &amp;&amp; res.length &gt; 0) {
                const customErr = new Error(`missing for ${res} types`);
                customErr.statusCode = 422;
                reject(customErr);
            }
            else {
                resolve();
            }
        })
    } catch (error) {
        return new Error(error);
    }
  }
  </code></pre>