title: Cloud Functions: check if document exists always return exists
body: <p>I'm checking if a document exists by using this cloud function (Typescript).
  The problem: the doc doens't exits and it returns exists....</p>
  
  <p>Thank you very much for the help and effort!</p>
  
  <pre><code>export const repeat2 = functions.https.onCall((data, context) =&gt; {
  
    console.log(data.message);
    console.log(data.count);
  
    const getDocument = admin.firestore().collection('key').doc(data.message).get();
  
          if(getDocument != null) {
            console.log('EXISTS');
          }
  
          else {console.log("doens't exist");}
  
      return {
          repeat_message: data.message,
      }
    });
  </code></pre>