title: Getting Object is possibly 'null' even after null checking
body: <pre><code>export async function getSingleUserQA(command: Command, period?: string[]) {
    let slackUserID;
  
    if (command &amp;&amp; command.text) {
      slackUserID = command.text.match(&quot;/(?&lt;=@)(.*?)(?=|)/g&quot;)[0];
    }
  }
  </code></pre>
  <p>I am being flagged that 'command' is possibly 'null' or 'undefined'. How come if I am making sure that command exists and command.text exists?</p>