Support listening to documents via onSnapshot

[Tanitolus]

Please add support for listening to documents.

https://cloud.google.com/nodejs/docs/reference/firestore/latest/firestore/documentreference#_google_cloud_firestore_DocumentReference_onSnapshot_member_1_

[FXschwartz]

@rrousselGit How would this even be implemented. I don't see anything that's exposed that we can use from the googleapis package.

[rrousselGit]

That's because there isn't at the moment.

But note that I am no longer at Invertase. Working on Firebase Admin isn't my responsibility anymore :)

[FXschwartz]

That's because there isn't at the moment.

But note that I am no longer at Invertase. Working on Firebase Admin isn't my responsibility anymore :)

Sounds good! Do you happen to know who we should be pinging for PR reviews or questions?

[rrousselGit]

Nope!