Deleting document breaks onSnapshot observer in emulator

[REQUIRED] Environment info

firebase-tools: 8.2.0

Platform: macOS

[REQUIRED] Test case

When deleting a document that has a query on a user auth property, the following error is throw on the snapshot listener. The goal is to observe all invites that has the users email. It works properly when in production, just not in the emulator.

Using these rules

match /invites/{inviteID} {
      function isSignedIn() {
        return request.auth != null;
      }
      function isUserInvite() {
        return request.auth.token.email != null &&
        request.auth.token.email == resource.data.user_email;
      }
      allow read: if isSignedIn() && isUserInvite();
      allow write: if true;
}

And this basic funciton to observe the collection.

firebase.firestore()
.collection("invites")
.where(`user_email`, '==', myUserEmail) // this would be the users email
.onSnapshot((snapshot) => {

  snapshot.forEach( doc => {
    console.log(doc.id, doc.data()) // log the invites that belong to the user
  })

})

Also have a stack overflow question started: https://stackoverflow.com/questions/61567689/firestore-onsnapshot-rules-throw-error-when-deleting-document

[REQUIRED] Steps to reproduce

// creates a new invite and the snapshot listener informs me 
await firebase.firestore()
.collection('invites')
.doc("invite_1")
.set({
  user_email: someUserEmail, // use the users email here 
  date_added: firebase.firestore.FieldValue.serverTimestamp()
})

// deletes the invite, but the snapshot throws an error
await firebase.firestore()
.doc(`invites/invite_1`)
.delete()

[REQUIRED] Expected behavior

The snapshot should always return the query - not throw an error because an item was deleted.

[REQUIRED] Actual behavior

The error FirebaseError: Null value error. for 'get' @ L91 is thrown.

[yuchenshi]

Fix coming in the next release.

[zanona]

I’m afraid this is still an issue when deleting the document from the emulator Firestore dashboard. When the document gets deleted from there Null value error is thrown.

*Edit: Never mind, it looks like that when read access is given based on resource, resource == null also needs to be allowed.