title: How to check if a field of 'type' is undefined in TypeScript?
body: <p>I have created a <code>type</code> in TypeScript which is a bit complex (has objects and maps within it).</p>
  <p>Is there a way to check if this type has any undefined value or should I go through every part of it to check if it is undefined?</p>
  <p>Would <code>typeof</code> be of service in such case?</p>