title: Property 'uid' does not exist on type '{ uid: string; token: DecodedIdToken; } | undefined'
body: <p>I am getting the following error in vscode :</p>
  <p><code>Property 'uid' does not exist on type '{ uid: string; token: DecodedIdToken; } | undefined'.</code></p>
  <p>with the following code :</p>
  <pre><code>export const getUid = functions.https.onCall((data, context) =&gt; {
      let { auth: {uid} } = context;
  });
  </code></pre>
  <p>I don't understand how <code>uid</code> could appear as &quot;not defined&quot; for a type defined as <code>{uid: string; .....}</code>.</p>
  <p>(Note that <code>functions.https.onCall</code> is from the <code>firebase</code> package.)</p>
  <p>Thank you in advance</p>