title: Null Propagation Error In Firebase Cloud Function
body: <p>I'm looking to deploy a cloud function where I'm reading from my database. I want to validate a field exists deep in an object so I was trying to use the null propagation operator <strong>?.</strong></p>
  <p><strong>Expected Behavior</strong>: if a deep key doesn't exist (or anything along the path), the expression below returns <em>undefined</em>.</p>
  <p><strong>Example Code:</strong> <code>if (doc.data()?.key?.subKey?.subSubKey) { // Do Stuff }</code></p>
  <p>When I deploy, I'm getting an error.</p>
  <blockquote>
  <p>Error: Error occurred while parsing your function triggers.</p>
  </blockquote>
  <p><strong>Clear Problem Statement</strong></p>
  <p>Am I doing something stupidly wrong? Are <strong>?.</strong> permitted in cloud functions? Its just vanilla JS right?</p>